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REPRINTED WITH PERMISSION OF IASP – PAIN 161 (2020) 880–888: Neck pain and headache after whiplash injury: a systematic review and meta-analysis
Abstract
Neck pain and headache are 2 of the most common complications of whiplash injury. Therefore, we performed a systematic literature search on PubMed and Embase for publications reporting on the prevalence of neck pain and headache after whiplash injury. The literature search identified 2709 citations of which 44 contained relevant original data. Of these, 27 studies provided data for the quantitative analysis. For non-population-based studies, the present metaanalysis showed that a pooled relative frequency of neck pain was 84% confidence interval (68–95%) and a pooled relative frequency of headache was 60% (46–73%), within 7 days after whiplash injury. At 12 months after injury, 38% (32–45%) of patients with whiplash still experienced neck pain, while 38% (18–60%) of whiplash patients reported headache at the same time interval after injury. However, we also found considerable heterogeneity among studies with I2-values ranging from 89% to 98% for the aforementioned meta-analyses. We believe that the considerable heterogeneity among studies underscores the need for clear-cut definitions of whiplash injury and standardized reporting guidelines for postwhiplash sequelae such as neck pain and headache. Future studies should seek to optimize these aspects paving the way for a better understanding of the clinical characteristics and natural course of whiplash-associated sequelae.
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Background
The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017) includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data.
Methods
We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting.
Findings
Globally, for females, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and haemoglobinopathies and haemolytic anaemias in both 1990 and 2017. For males, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and tuberculosis including latent tuberculosis infection in both 1990 and 2017. In terms of YLDs, low back pain, headache disorders, and dietary iron deficiency were the leading Level 3 causes of YLD counts in 1990, whereas low back pain, headache disorders, and depressive disorders were the leading causes in 2017 for both sexes combined. All-cause age-standardised YLD rates decreased by 3·9% (95% uncertainty interval [UI] 3·1–4·6) from 1990 to 2017; however, the all-age YLD rate increased by 7·2% (6·0–8·4) while the total sum of global YLDs increased from 562 million (421–723) to 853 million (642–1100). The increases for males and females were similar, with increases in all-age YLD rates of 7·9% (6·6–9·2) for males and 6·5% (5·4–7·7) for females. We found significant differences between males and females in terms of age-standardised prevalence estimates for multiple causes. The causes with the greatest relative differences between sexes in 2017 included substance use disorders (3018 cases [95% UI 2782–3252] per 100 000 in males vs s1400 [1279–1524] per 100 000 in females), transport injuries (3322 [3082–3583] vs 2336 [2154–2535]), and self-harm and interpersonal violence (3265 [2943–3630] vs 5643 [5057–6302]).
Interpretation
Global all-cause age-standardised YLD rates have improved only slightly over a period spanning nearly three decades. However, the magnitude of the non-fatal disease burden has expanded globally, with increasing numbers of people who have a wide spectrum of conditions. A subset of conditions has remained globally pervasive since 1990, whereas other conditions have displayed more dynamic trends, with different ages, sexes, and geographies across the globe experiencing varying burdens and trends of health loss. This study emphasises how global improvements in premature mortality for select conditions have led to older populations with complex and potentially expensive diseases, yet also highlights global achievements in certain domains of disease and injury.
Background: As mortality rates decline, life expectancy increases, and populations age, non-fatal outcomes of diseases and injuries are becoming a larger component of the global burden of disease. The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) provides a comprehensive assessment of prevalence, incidence, and years lived with disability (YLDs) for 328 causes in 195 countries and territories from 1990 to 2016.
Methods: We estimated prevalence and incidence for 328 diseases and injuries and 2982 sequelae, their non-fatal consequences. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between incidence, prevalence, remission, and cause of death rates for each condition. For some causes, we used alternative modelling strategies if incidence or prevalence needed to be derived from other data. YLDs were estimated as the product of prevalence and a disability weight for all mutually exclusive sequelae, corrected for comorbidity and aggregated to cause level. We updated the Socio-demographic Index (SDI), a summary indicator of income per capita, years of schooling, and total fertility rate. GBD 2016 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER).
Findings: Globally, low back pain, migraine, age-related and other hearing loss, iron-deficiency anaemia, and major depressive disorder were the five leading causes of YLDs in 2016, contributing 57·6 million (95% uncertainty interval [UI] 40·8–75·9 million [7·2%, 6·0–8·3]), 45·1 million (29·0–62·8 million [5·6%, 4·0–7·2]), 36·3 million (25·3–50·9 million [4·5%, 3·8–5·3]), 34·7 million (23·0–49·6 million [4·3%, 3·5–5·2]), and 34·1 million (23·5–46·0 million [4·2%, 3·2–5·3]) of total YLDs, respectively. Age-standardised rates of YLDs for all causes combined decreased between 1990 and 2016 by 2·7% (95% UI 2·3–3·1). Despite mostly stagnant age-standardised rates, the absolute number of YLDs from non-communicable diseases has been growing rapidly across all SDI quintiles, partly because of population growth, but also the ageing of populations. The largest absolute increases in total numbers of YLDs globally were between the ages of 40 and 69 years. Age-standardised YLD rates for all conditions combined were 10·4% (95% UI 9·0–11·8) higher in women than in men. Iron-deficiency anaemia, migraine, Alzheimer's disease and other dementias, major depressive disorder, anxiety, and all musculoskeletal disorders apart from gout were the main conditions contributing to higher YLD rates in women. Men had higher age-standardised rates of substance use disorders, diabetes, cardiovascular diseases, cancers, and all injuries apart from sexual violence. Globally, we noted much less geographical variation in disability than has been documented for premature mortality. In 2016, there was a less than two times difference in age-standardised YLD rates for all causes between the location with the lowest rate (China, 9201 YLDs per 100 000, 95% UI 6862–11943) and highest rate (Yemen, 14 774 YLDs per 100 000, 11 018–19 228).
Interpretation: The decrease in death rates since 1990 for most causes has not been matched by a similar decline in age-standardised YLD rates. For many large causes, YLD rates have either been stagnant or have increased for some causes, such as diabetes. As populations are ageing, and the prevalence of disabling disease generally increases steeply with age, health systems will face increasing demand for services that are generally costlier than the interventions that have led to declines in mortality in childhood or for the major causes of mortality in adults. Up-to-date information about the trends of disease and how this varies between countries is essential to plan for an adequate health-system response.
Classification has played a major role in the diagnosis of primary headache conditions including migraine with and without aura. With many updates and changes, the International Classification of Headache Disorders (ICHD)-3 beta is currently considered as the gold standard for classification of migraine and other headaches. Correct diagnosis of migraine and its subtypes is a first step toward appropriate treatment and crucial to minimizing disability and optimizing health-related quality of life. The ICHD-3 beta version represents the state of the art in migraine diagnosis but is expected to evolve as biological knowledge advances. Future research should focus on identification of biologically homogeneous subgroups of migraine based on genes and biomarkers.
Background
Whiplash injuries are among the leading injuries related to car crashes and it is important to determine the prognostic factors that predict the outcome of patients with these injuries. This meta-review aims to identify factors that are associated with outcome after acute whiplash injury. Materials and methodsA systematic search for all systematic reviews on outcome prediction of acute whiplash injury was conducted across several electronic databases. The search was limited to publications in English, and there were no geographical or time of publication restrictions. Quality appraisal was conducted with A Measurement Tool to Assess Systematic Reviews. ResultsThe initial search yielded 207 abstracts; of these, 195 were subsequently excluded by topic or method. Twelve systematic reviews with moderate quality were subsequently included in the analysis. Post-injury pain and disability, whiplash grades, cold hyperalgesia, post-injury anxiety, catastrophizing, compensation and legal factors, and early healthcare use were associated with continuation of pain and disability in patients with whiplash injury. Post-injury magnetic resonance imaging or radiographic findings, motor dysfunctions, or factors related to the collision were not associated with continuation of pain and disability in patients with whiplash injury. Evidence on demographic and three psychological factors and prior pain was conflicting, and there is a shortage of evidence related to the significance of genetic factors. Conclusions
This meta-review suggests an association between initial pain and anxiety and the outcome of acute whiplash injury, and less evidence for an association with physical factors. Level of evidenceLevel 1.
Background
This study aims to compare health status and quality of life five years after a road accident between casualties with whiplash versus other mild injuries, to compare evolution of quality of life at 1 and 5 years after the accident, and to explore the relation between initial injury (whiplash vs. other) and quality of life.
Methods
The study used data from the ESPARR cohort (a representative cohort of road accident casualties) and included 167 casualties with “pure” whiplash and a population of 185 casualties with other mild injuries (MAIS-1). All subjects with lesions classified as cervical contusion (AIS code 310402) or neck sprain (AIS code 640278) were considered as whiplash casualties. Diagnosis was made by physicians, at the outset of hospital care, based on interview, clinical findings and X-ray. Whiplash injuries were then classified following the Quebec classification (grades 1 and 2). Quality of life was assessed on the WHOQoL-Bref questionnaire. Correlations between explanatory variables and quality of life were explored by Poisson regression and variance analysis.
Results
Between 1 and 5 years, global QoL improved for both whiplash and non-whiplash casualties; but, considering the two whiplash groups separately, improvement in grade 2 was much less than in grade 1. At 5 years, grade-2 whiplash casualties were more dissatisfied with their health (39.4 %; p < 0.05) than non-whiplash (24.3 %) or grade-1 whiplash casualties (27.0 %). Deteriorated quality of life in the mental, social and environmental domains was mainly related to psychological and socioeconomic factors for both whiplash and other mildly injured road-accident casualties. While PTSD was a major factor for the physical domain, whiplash remained a predictive factor after adjustment on PTSD; unsatisfactory health at 5 years, with deteriorated quality of life in the physical domain, was observed specifically in the whiplash group, pain playing a predominant intermediate role.
Conclusions
Deteriorated quality of life in the physical domain remained 5 years after the accident, specifically in the grade-2 whiplash group, pain playing a predominant intermediate role, which may be in line with the hypothesis of neuropathic pain.
10-22% of individuals sustaining whiplash trauma develop persistent symptoms resulting in reduced working ability and decreased quality of life, but it is poorly understood why some people do not recover. Various collision and post-collision risk factors have been studied, but little is known about pre-collision risk factors. In particular, the impact of sickness and socioeconomic factors before the collision on recovery is sparsely explored. The aim of this study was to examine if welfare payments received within five years pre-collision predict neck pain and negative change in provisional situation one year post-collision.
719 individuals with acute whiplash trauma consecutively recruited from emergency departments or primary care after car accidents in Denmark completed questionnaires on socio-demographic and health factors immediately after the collision. After 12 months, a visual analogue scale on neck pain intensity was completed. 3595 matched controls in the general population were sampled, and national public register data on social benefits and any other welfare payments were obtained for participants with acute whiplash trauma and controls from five years pre-collision to 15 months after. Participants with acute whiplash trauma who had received sickness benefit for more than 12 weeks pre-collision had increased odds for negative change in future provisional situation (Odds Ratio (OR) (95% Confidence Interval (CI) = 3.8 (2.1;7.1)) and future neck pain (OR (95%CI) = 3.3 (1.8;6.3)), controlling for other known risk factors. Participants with acute whiplash trauma had weaker attachment to labour market (more weeks of sick leave (χ2(2) = 36.7, p < 0.001) and unemployment (χ2(2) = 12.5, p = 0.002)) pre-collision compared with controls. Experiencing a whiplash trauma raised the odds for future negative change in provisional situation (OR (95%CI) = 3.1 (2.3;4.4)) compared with controls.
Sick leave before the collision strongly predicted prolonged recovery following whiplash trauma. Participants with acute whiplash trauma had weaker attachment to labour market pre-collision compared with the general population. Neck pain at inclusion predicted future neck pain. Acute whiplash trauma may trigger pre-existing vulnerabilities increasing risk of developing whiplash-associated disorders.
Meta-analysis is a method to obtain a weighted average of results from various studies. In addition to pooling effect sizes, meta-analysis can also be used to estimate disease frequencies, such as incidence and prevalence. In this article we present methods for the meta-analysis of prevalence. We discuss the logit and double arcsine transformations to stabilise the variance. We note the special situation of multiple category prevalence, and propose solutions to the problems that arise. We describe the implementation of these methods in the MetaXL software, and present a simulation study and the example of multiple sclerosis from the Global Burden of Disease 2010 project. We conclude that the double arcsine transformation is preferred over the logit, and that the MetaXL implementation of multiple category prevalence is an improvement in the methodology of the meta-analysis of prevalence.
Funnel plots, and tests for funnel plot asymmetry, have been widely used to examine bias in the results of meta-analyses. Funnel plot asymmetry should not be equated with publication bias, because it has a number of other possible causes. This article describes how to interpret funnel plot asymmetry, recommends appropriate tests, and explains the implications for choice of meta-analysis modelThe 1997 paper describing the test for funnel plot asymmetry proposed by Egger et al 1 is one of the most cited articles in the history of BMJ.1 Despite the recommendations contained in this and subsequent papers,2 3 funnel plot asymmetry is often, wrongly, equated with publication or other reporting biases. The use and appropriate interpretation of funnel plots and tests for funnel plot asymmetry have been controversial because of questions about statistical validity,4 disputes over appropriate interpretation,3 5 6 and low power of the tests.2This article recommends how to examine and interpret funnel plot asymmetry (also known as small study effects2) in meta-analyses of randomised controlled trials. The recommendations are based on a detailed MEDLINE review of literature published up to 2007 and discussions among methodologists, who extended and adapted guidance previously summarised in the Cochrane Handbook for Systematic Reviews of Interventions.7What is a funnel plot?A funnel plot is a scatter plot of the effect estimates from individual studies against some measure of each study’s size or precision. The standard error of the effect estimate is often chosen as the measure of study size and plotted on the vertical axis8 with a reversed scale that places the larger, most powerful studies towards the top. The effect estimates from smaller studies should scatter more widely at the bottom, with the spread narrowing among larger studies.9 In the absence of bias and between study heterogeneity, the scatter will be due to sampling variation alone and the plot will resemble a symmetrical inverted funnel (fig 1⇓). A triangle centred on a fixed effect summary estimate and extending 1.96 standard errors either side will include about 95% of studies if no bias is present and the fixed effect assumption (that the true treatment effect is the same in each study) is valid. The appendix on bmj.com discusses choice of axis in funnel plots.View larger version:In a new windowDownload as PowerPoint SlideFig 1 Example of symmetrical funnel plot. The outer dashed lines indicate the triangular region within which 95% of studies are expected to lie in the absence of both biases and heterogeneity (fixed effect summary log odds ratio±1.96×standard error of summary log odds ratio). The solid vertical line corresponds to no intervention effectImplications of heterogeneity, reporting bias, and chance Heterogeneity, reporting bias, and chance may all lead to asymmetry or other shapes in funnel plots (box). Funnel plot asymmetry may also be an artefact of the choice of statistics being plotted (see appendix). The presence of any shape in a funnel plot is contingent on the studies having a range of standard errors, since otherwise they would lie on a horizontal line.Box 1: Possible sources of asymmetry in funnel plots (adapted from Egger et al1)Reporting biasesPublication bias: Delayed publication (also known as time lag or pipeline) bias Location biases (eg, language bias, citation bias, multiple publication bias)Selective outcome reportingSelective analysis reportingPoor methodological quality leading to spuriously inflated effects in smaller studiesPoor methodological designInadequate analysisFraudTrue heterogeneitySize of effect differs according to study size (eg, because of differences in the intensity of interventions or in underlying risk between studies of different sizes)ArtefactualIn some circumstances, sampling variation can lead to an association between the intervention effect and its standard errorChanceAsymmetry may occur by chance, which motivates the use of asymmetry testsHeterogeneityStatistical heterogeneity refers to differences between study results beyond those attributable to chance. It may arise because of clinical differences between studies (for example, setting, types of participants, or implementation of the intervention) or methodological differences (such as extent of control over bias). A random effects model is often used to incorporate heterogeneity in meta-analyses. If the heterogeneity fits with the assumptions of this model, a funnel plot will be symmetrical but with additional horizontal scatter. If heterogeneity is large it may overwhelm the sampling error, so that the plot appears cylindrical.Heterogeneity will lead to funnel plot asymmetry if it induces a correlation between study sizes and intervention effects.5 For example, substantial benefit may be seen only in high risk patients, and these may be preferentially included in early, small studies.10 Or the intervention may have been implemented less thoroughly in larger studies, resulting in smaller effect estimates compared with smaller studies.11Figure 2⇓ shows funnel plot asymmetry arising from heterogeneity that is due entirely to there being three distinct subgroups of studies, each with a different intervention effect.12 The separate funnels for each subgroup are symmetrical. Unfortunately, in practice, important sources of heterogeneity are often unknown.View larger version:In a new windowDownload as PowerPoint SlideFig 2 Illustration of funnel plot asymmetry due to heterogeneity, in the form of three distinct subgroups of studies. Funnel plot including all studies (top left) shows clear asymmetry (P<0.001 from Egger test for funnel plot asymmetry). P values for each subgroup are all >0.49.Differences in methodological quality may also cause heterogeneity and lead to funnel plot asymmetry. Smaller studies tend to be conducted and analysed with less methodological rigour than larger studies,13 and trials of lower quality also tend to show larger intervention effects.14 15Reporting biasReporting biases arise when the dissemination of research findings is influenced by the nature and direction of results. Statistically significant “positive” results are more likely to be published, published rapidly, published in English, published more than once, published in high impact journals, and cited by others.16 17 18 19 Data that would lead to negative results may be filtered, manipulated, or presented in such a way that they become positive.14 20 Reporting biases can have three types of consequence for a meta-analysis:A systematic review may fail to locate an eligible study because all information about it is suppressed or hard to find (publication bias) A located study may not provide usable data for the outcome of interest because the study authors did not consider the result sufficiently interesting (selective outcome reporting) A located study may provide biased results for some outcome—for example, by presenting the result with the smallest P value or largest effect estimate after trying several analysis methods (selective analysis reporting).These biases may cause funnel plot asymmetry if statistically significant results suggesting a beneficial effect are more likely to be published than non-significant results. Such asymmetry may be exaggerated if there is a further tendency for smaller studies to be more prone to selective suppression of results than larger studies. This is often assumed to be the case for randomised trials. For instance, it is probably more difficult to make a large study disappear without trace, while a small study can easily be lost in a file drawer.21 The same may apply to specific outcomes—for example, it is difficult not to report on mortality or myocardial infarction if these are outcomes of a large study. Smaller studies have more sampling error in their effect estimates. Thus even though the risk of a false positive significant finding is the same, multiple analyses are more likely to yield a large effect estimate that may seem worth publishing. However, biases may not act this way in real life; funnel plots could be symmetrical even in the presence of publication bias or selective outcome reporting19 22—for example, if the published findings point to effects in different directions but unreported results indicate neither direction. Alternatively, bias may have affected few studies and therefore not cause glaring asymmetry.ChanceThe role of chance is critical for interpretation of funnel plots because most meta-analyses of randomised trials in healthcare contain few studies.2 Investigations of relations across studies in a meta-analysis are seriously prone to false positive findings when there is a small number of studies and heterogeneity across studies,23 and this may affect funnel plot symmetry.Interpreting funnel plot asymmetryAuthors of systematic reviews should distinguish between possible reasons for funnel plot asymmetry (box 1). Knowledge of the intervention, and the circumstances in which it was implemented in different studies, can help identify causes of asymmetry in funnel plots, which should also be interpreted in the context of susceptibility to biases of research in the field of interest. Potential conflicts of interest, whether outcomes and analyses have been standardised, and extent of trial registration may need to be considered. For example, studies of antidepressants generate substantial conflicts of interest because the drugs generate vast sales revenues. Furthermore, there are hundreds of outcome scales, analyses can be very flexible, and trial registration was uncommon until recently.24 Conversely, in a prospective meta-analysis where all data are included and all analyses fully standardised and conducted according to a predetermined protocol, publication or reporting biases cannot exist. Reporting bias is therefore more likely to be a cause of an asymmetric plot in the first situation than in the second.Terrin et al found that researchers were poor at identifying publication bias from funnel plots.5 Including contour lines corresponding to perceived milestones of statistical significance (P=0.01, 0.05, 0.1, etc) may aid visual interpretation.25 If studies seem to be missing in areas of non-significance (fig 3⇓, top) then asymmetry may be due to reporting bias, although other explanations should still be considered. If the supposed missing studies are in areas of higher significance or in a direction likely to be considered desirable to their authors (fig 3⇓, bottom), asymmetry is probably due to factors other than reporting bias. View larger version:In a new windowDownload as PowerPoint SlideFig 3 Contour enhanced funnel plots. In the top diagram there is a suggestion of missing studies in the middle and right of the plot, broadly in the white area of non-significance, making publication bias plausible. In the bottom diagram there is a suggestion of missing studies on the bottom left hand side of the plot. Since most of this area contains regions of high significance, publication bias is unlikely to be the underlying cause of asymmetryStatistical tests for funnel plot asymmetryA test for funnel plot asymmetry (sometimes referred to as a test for small study effects) examines whether the association between estimated intervention effects and a measure of study size is greater than might be expected to occur by chance. These tests typically have low power, so even when a test does not provide evidence of asymmetry, bias cannot be excluded. For outcomes measured on a continuous scale a test based on a weighted linear regression of the effect estimates on their standard errors is straightforward.1 When outcomes are dichotomous and intervention effects are expressed as odds ratios, this corresponds to an inverse variance weighted linear regression of the log odds ratio on its standard error.2 Unfortunately, there are statistical problems because the standard error of the log odds ratio is mathematically linked to the size of the odds ratio, even in the absence of small study effects.2 4 Many authors have therefore proposed alternative tests (see appendix on bmj.com).4 26 27 28Because it is impossible to know the precise mechanism(s) leading to funnel plot asymmetry, simulation studies (in which tests are evaluated on large numbers of computer generated datasets) are required to evaluate test characteristics. Most have examined a range of assumptions about the extent of reporting bias by selectively removing studies from simulated datasets.26 27 28 After reviewing the results of these studies, and based on theoretical considerations, we formulated recommendations on testing for funnel plot asymmetry (box 2). The appendix describes the proposed tests, explains the reasons that some were not recommended, and discusses funnel plots for intervention effects measured as risk ratios, risk differences, and standardised mean differences. Our recommendations imply that tests for funnel plot asymmetry should be used in only a minority of meta-analyses.29Box 2: Recommendations on testing for funnel plot asymmetryAll types of outcomeAs a rule of thumb, tests for funnel plot asymmetry should not be used when there are fewer than 10 studies in the meta-analysis because test power is usually too low to distinguish chance from real asymmetry. (The lower the power of a test, the higher the proportion of “statistically significant” results in which there is in reality no association between study size and intervention effects). In some situations—for example, when there is substantial heterogeneity—the minimum number of studies may be substantially more than 10Test results should be interpreted in the context of visual inspection of funnel plots— for example, are there studies with markedly different intervention effect estimates or studies that are highly influential in the asymmetry test? Even if an asymmetry test is statistically significant, publication bias can probably be excluded if small studies tend to lead to lower estimates of benefit than larger studies or if there are no studies with significant resultsWhen there is evidence of funnel plot asymmetry, publication bias is only one possible explanation (see box 1)As far as possible, testing strategy should be specified in advance: choice of test may depend on the degree of heterogeneity observed. Applying and reporting many tests is discouraged: if more than one test is used, all test results should be reported Tests for funnel plot asymmetry should not be used if the standard errors of the intervention effect estimates are all similar (the studies are of similar sizes)Continuous outcomes with intervention effects measured as mean differencesThe test proposed by Egger et al may be used to test for funnel plot asymmetry.1 There is no reason to prefer more recently proposed tests, although their relative advantages and disadvantages have not been formally examined. General considerations suggest that the power will be greater than for dichotomous outcomes but that use of the test with substantially fewer than 10 studies would be unwiseDichotomous outcomes with intervention effects measured as odds ratiosThe tests proposed by Harbord et al26 and Peters et al27 avoid the mathematical association between the log odds ratio and its standard error when there is a substantial intervention effect while retaining power compared with alternative tests. However, false positive results may still occur if there is substantial between study heterogeneityIf there is substantial between study heterogeneity (the estimated heterogeneity variance of log odds ratios, τ2, is >0.1) only the arcsine test including random effects, proposed by Rücker et al, has been shown to work reasonably well.28 However, it is slightly conservative in the absence of heterogeneity and its interpretation is less familiar than for other tests because it is based on an arcsine transformation.When τ2 is <0.1, one of the tests proposed by Harbord et al,26 Peters et al,27 or Rücker et al28 can be used. Test performance generally deteriorates as τ2 increases.Funnel plots and meta-analysis modelsFixed and random effects modelsFunnel plots can help guide choice of meta-analysis method. Random effects meta-analyses weight studies relatively more equally than fixed effect analyses by incorporating the between study variance into the denominator of each weight. If effect estimates are related to standard errors (funnel plot asymmetry), the random effects estimate will be pulled more towards findings from smaller studies than the fixed effect estimate will be. Random effects models can thus have undesirable consequences and are not always conservative.30The trials of intravenous magnesium after myocardial infarction provide an extreme example of the differences between fixed and random effects analyses that can arise in the presence of funnel plot asymmetry.31 Beneficial effects on mortality, found in a meta-analysis of small studies,32 were subsequently contradicted when the very large ISIS-4 study found no evidence of benefit.33 A contour enhanced funnel plot (fig 4⇓) gives a clear visual impression of asymmetry, which is confirmed by small P values from the Harbord and Peters tests (P<0.001 and P=0.002 respectively).View larger version:In a new windowDownload as PowerPoint SlideFig 4 Contour enhanced funnel plot for trials of the effect of intravenous magnesium on mortality after myocardial infarctionFigure 5⇓ shows that in a fixed effect analysis ISIS-4 receives 90% of the weight, and there is no evidence of a beneficial effect. However, there is clear evidence of between study heterogeneity (P<0.001, I2=68%), and in a random effects analysis the small studies dominate so that intervention appears beneficial. To interpret the accumulated evidence, it is necessary to make a judgment about the validity or relevance of the combined evidence from the smaller studies compared with that from ISIS-4. The contour enhanced funnel plot suggests that publication bias does not completely explain the asymmetry, since many of the beneficial effects reported from smaller studies were not significant. Plausible explanations for these results are that methodological flaws in the smaller studies, or changes in the standard of care (widespread adoption of treatments such as aspirin, heparin, and thrombolysis), led to apparent beneficial effects of magnesium. This belief was reinforced by the subsequent publication of the MAGIC trial, in which magnesium added to these treatments which also found no evidence of benefit on mortality (odds ratio 1.0, 95% confidence interval 0.8 to 1.1).34View larger version:In a new windowDownload as PowerPoint SlideFig 5 Comparison of fixed and random effects meta-analytical estimates of the effect of intravenous magnesium on mortality after myocardial infarctionWe recommend that when review authors are concerned about funnel plot asymmetry in a meta-analysis with evidence of between study heterogeneity, they should compare the fixed and random effects estimates of the intervention effect. If the random effects estimate is more beneficial, authors should consider whether it is plausible that the intervention is more effective in smaller studies. Formal investigations of heterogeneity of effects may reveal explanations for funnel plot asymmetry, in which case presentation of results should focus on these. If larger studies tend to be methodologically superior to smaller studies, or were conducted in circumstances more typical of the use of the intervention in practice, it may be appropriate to include only larger studies in the meta-analysis.Extrapolation of a funnel plot regression lineAn assumed relation between susceptibility to bias and study size can be exploited by extrapolating within a funnel plot. When funnel plot asymmetry is due to bias rather than substantive heterogeneity, it is usually assumed that results from larger studies are more believable than those from smaller studies because they are less susceptible to methodological flaws or reporting biases. Extrapolating a regression line on a funnel plot to minimum bias (maximum sample size) produces a meta-analytical estimate that can be regarded as corrected for such biases.35 36 37 However, because it is difficult to distinguish between asymmetry due to bias and asymmetry due to heterogeneity or chance, the broad applicability of such approaches is uncertain. Further approaches to adjusting for publication bias are described and discussed in the appendix.DiscussionReporting biases are one of a number of possible explanations for the associations between study size and effect size that are displayed in asymmetric funnel plots. Examining and testing for funnel plot asymmetry, when appropriate, is an important means of addressing bias in meta-analyses, but the multiple causes of asymmetry and limited power of asymmetry tests mean that other ways to address reporting biases are also of importance. Searches of online trial registries can identify unpublished trials, although they do not currently guarantee access to trial protocols and results. When there are no registered but unpublished trials, and the outcome of interest is reported by all trials, restricting meta-analyses to registered trials should preclude publication bias. Recent comparisons of results of published trials with those submitted for regulatory approval have also provided clear evidence of reporting bias.38 39 Methods for dealing with selective reporting of outcomes have been described elsewhere. 40Our recommendations apply to meta-analyses of randomised trials, and their applicability in other contexts such as meta-analyses of epidemiological or diagnostic test studies is unclear.41 The performance of tests for funnel plot asymmetry in these contexts is likely to differ from that in meta-analyses of randomised trials. Further factors, such as confounding and precision of measurements, may cause a relation between study size and effect estimates in observational studies. For example, large studies based on routinely collected data might not fully control confounding compared with smaller, purpose designed studies that collected a wide range of potential confounding variables. Alternatively, larger studies might use self reported exposure levels, which are more error prone, while smaller studies used precise measuring instruments. However, simulation studies have usually not considered such situations. An exception is for diagnostic studies, where large imbalances in group sizes and substantial odds ratios lead to poor performance of some tests: that proposed by Deeks et al was designed for use in this context.4Summary points Inferences on the presence of bias or heterogeneity should consider different causes of funnel plot asymmetry and should not be based on visual inspection of funnel plots aloneThey should be informed by contextual factors, including the plausibility of publication bias as an explanation for the asymmetryTesting for funnel plot asymmetry should follow the recommendations detailed in this articleThe fixed and random effects estimates of the intervention effect should be compared when funnel plot asymmetry exists in a meta-analysis with between study heterogeneityNotesCite this as: BMJ 2011;342:d4002FootnotesContributors: All authors contributed to the drafting and editing of the manuscript. DA, JC, JD, RMH, JPTH, JPAI, DRJ, DM, JP, GR, JACS, AJS and JT contributed to the chapter in the Cochrane Handbook for Systematic Reviews of Interventions on which our recommendations on testing for funnel plot asymmetry are based. JACS will act as guarantor.Funding: Funded in part by the Cochrane Collaboration Bias Methods Group, which receives infrastructure funding as part of a commitment by the Canadian Institutes of Health Research (CIHR) and the Canadian Agency for Drugs and Technologies in Health (CADTH) to fund Canadian based Cochrane entities. This supports dissemination activities, web hosting, travel, training, workshops and a full time coordinator position. JPTH was funded by MRC Grant U.1052.00.011. DGA is supported by Cancer Research UK. GR was supported by a grant from Deutsche Forschungsgemeinschaft (FOR 534 Schw 821/2-2).Competing interests. 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In more than 90% of whiplash accidents a good explanation regarding the association between trauma mechanism, organic pathology, and persistent symptoms has failed to be provided.
We predicted that the severity of chronic whiplash-associated disorder (WAD), measured as number of whiplash symptoms, pain duration, pain-related disability, and degree of somatisation would be associated with the number of post-traumatic stress disorder symptoms (PTSD). Secondly, we expected attachment-anxiety to be a vulnerability factor in relation to both PTSD and WAD.
Data were collected from 1,349 women and 360 men suffering from WAD from the Danish Society for Polio, Traffic, and Accident Victims. The PTSD symptoms were measured by the Harvard Trauma Questionnaire. All three core PTSD clusters were included: re-experiencing, avoidance, and hyperarousal. Attachment security was measured along the two dimensions, attachment-anxiety and attachment-avoidance, by the Revised Adult Attachment Scale.
PTSD symptoms were significantly related to the severity of WAD. In particular, the PTSD clusters of avoidance and hyperarousal were associated with the number of whiplash symptoms, disability, and somatisation. Attachment-anxiety was significantly related to PTSD symptoms and somatisation but not to pain and disability. A co-morbidity of 38.8% was found between the PTSD diagnosis and WAD, and about 20% of the sample could be characterised as securely attached.
The PTSD clusters of avoidance and hyperarousal were significantly associated with severity of WAD. The study emphasises the importance of assessing PTSD symptomatology after whiplash injury. Furthermore, it highlights that attachment theory may facilitate the understanding of why some people are more prone to develop PTSD and WAD than others.
To examine the annual incidence of acute whiplash injuries after road traffic crashes in a geographic catchment area in Northern Sweden during the period 2000-2009.
Descriptive epidemiology determined by prospectively collected data from a defined population.
The study was conducted at a public hospital in Sweden.
The population of the hospital's catchment area (136,600 inhabitants in 1999 and 144,500 in 2009).
At the emergency department, all injured persons (approximately 11,000 per year) were asked to answer a questionnaire about the injury incident. Data from the medical records also were analyzed. From 2000-2009, 15,506 persons were injured in vehicle crashes. Persons who were subject to an acute neck injury within whiplash-associated disorder grades 1-3 were included. The overall and annual incidences were calculated as incidence. Age, gender, type of injury event, and direction of impact were described. The incidences were compared with national statistics on insurance claims from 2003, 2007, and 2008 to detect changes in the proportions of claims.
The annual incidence of acute whiplash injuries. Secondary outcome measures were types of injury events, age and gender distribution, changes in the proportion of rear-end crashes during 2000-2009, and changes in the proportion of insurance claims during 2003-2008.
During 2000-2009, 3297 cases of acute whiplash injury were encountered. The overall incidence was 235/100,000/year. The average yearly increase in incidence was 1.0%. Women comprised 51.9% and men 48.1% of the injured. Car occupants (86.4%) and bicycle riders (6.1%) were most frequently injured. The proportion of rear-end crashes decreased from 55% to 45% from 2000-2009. The proportion of insurance claims significantly decreased between 2003 and 2008 (P < .0001, χ(2) test).
The incidence of emergency department visits attributable to acute whiplash injuries after road traffic crashes have been relatively stable during the past decade in our area, except in 2007 and 2008, when a peak occurred.
Few studies have focused on the differences between persons who are recovered after whiplash injury and those who suffer from persistent disability. The primary aim of this study was therefore to examine differences in symptoms, psychological factors and life satisfaction between subjects classified as recovered and those with persistent disability five years after whiplash injury based on the Neck Disability Index (NDI).
A set of questionnaires was answered by 158 persons (75 men, 83 women) to assess disability (NDI), pain intensity (VAS), whiplash-related symptoms (Rivermead Post-Concussion Symptoms Questionnaire, RPQ), post-traumatic stress (Impact of Event Scale, IES), depression (Beck's depression inventory, BDI) and life satisfaction (LiSat-11).The participants were divided into three groups based on the results of the NDI: recovered (34.8%), mild disability (37.3%) and moderate/severe disability (27.3%).
The moderate/severe group reported significantly higher VAS, BDI and IES scores and lower level of physical health and psychological health compared to the mild and the recovered groups. Less significant differences were reported between the mild and the recovered groups.
The group with the highest disability score reported most health problems with pain, symptoms, depression, post-traumatic stress and decreased life satisfaction. These findings indicate that classifying these subjects into subgroups based on disability levels makes it possible to optimize the management and treatment after whiplash injury.
The aims of this study were: to describe the frequency of whiplash-related symptoms and psychological factors in persons 5 years after a whiplash injury; to study the relationship between symptoms and psychological factors; to examine gender differences; and to investigate the cause of sick leave.
Questionnaires addressing neck pain, pain intensity, whiplash-related symptoms, post-traumatic stress, depression, social support and life satisfaction were used.
Neck pain was reported by 59% of subjects, whiplash-related symptoms (Rivermead Post-Concussion Symptoms Questionnaire, RPQ) by 76%, depression (Beck's Depression Inventory, BDI) by 22%, and post-traumatic stress (Impact of Event Scale, IES), by 38%. The scores of pain intensity and RPQ were correlated to BDI, IES and LiSat-11 scores. Men reported a lower level of quality of social support than women. Men reporting many symptoms also reported reduced availability of social interaction, whereas women with many symptoms reported reduced availability of attachment (i.e. lack of intimate partner, close family and friends). A multivariate logistic regression showed an association between sick leave and depression.
These findings indicate the importance of assessing possible relationships between symptoms, depression and post-traumatic stress in persons with long-term problems after whiplash injury, and of treating existing symptoms, especially depression. Because social support may play a role in recovery, social relationships should also be examined.
Prospective cohort study.
To investigate the consequences of neck pain after motor vehicle accidents in terms of disability for work and the relationship this has with symptom and work-related factors.
Previous studies on work disability related to whiplash are very heterogeneous, are often limited in sample size and show a wide variability in terms of results. A relationship has been suggested between poor recovery from or persistent work disability after whiplash and female gender, older age, marital status, heavy manual work, self-employment, prior psychological problems, subjective complaints of poor concentration, pain catastrophizing, and kinesiophobia.
Individuals with neck complaints after involvement in traffic accidents, who initiated compensation claim procedures with a Dutch insurance company (n = 879), were sent questionnaires (Q1) concerning the accident, the injuries that they had sustained, their complaints at that time, and questions regarding work and disability. The course of complaints and work disability was monitored at 6 (Q2) and 12 months (Q3) after the accident.
A total of 58.8% of the population with neck complaints studied was work-disabled after the accident. Age and impaired concentration complaints after 1 month were found to be related to work disability at 1 year, independent of physical complaints and work characteristics.
Age and concentration complaints were important independent predictors of long-lasting work disability, whereas no evidence emerged to indicate that the degree of manual labor (blue or white collar work) or educational level was involved in persistent work disability in postwhiplash syndrome. The current results suggest that work disability could benefit most from interventions related to recovery from cognitive complaints and less from physically related interventions.
In Lithuania, there is little awareness of the notion that chronic symptoms may result from rear end collisions via the so-called whiplash injury. After most such collisions no contact with the health service is established. An opportunity therefore exists to study post-traumatic pain without the confounding factors present in western societies.
In a prospective, controlled inception cohort study, 210 victims of a rear end collision were consecutively identified from the daily records of the Kaunas traffic police. Neck pain and headache were evaluated by mailed questionnaires shortly after the accident, after 2 months, and after 1 year. As controls, 210 sex and age matched subjects were randomly taken from the population register of the same geographical area and evaluated for the same symptoms immediately after their identification and after 1 year.
Initial pain was reported by 47% of accident victims; 10% had neck pain alone, 18% had neck pain together with headache, and 19% had headache alone. The median duration of the initial neck pain was 3 days and maximal duration 17 days. The median duration of headache was 4.5 hours and the maximum duration was 20 days. After 1 year, there were no significant differences between the accident victims and the control group concerning frequency and intensity of these symptoms.
In a country were there is no preconceived notion of chronic pain arising from rear end collisions, and thus no fear of long term disability, and usually no involvement of the therapeutic community, insurance companies, or litigation, symptoms after an acute whiplash injury are self limiting, brief, and do not seem to evolve to the so-called late whiplash syndrome.
Background:
Some patients suffer from long-lasting symptoms after whiplash injury. However, there are few reports on the long-term changes in the cervical spine after whiplash injury using imaging tests. The purpose of this longitudinal study was to determine the changes on MRI of the cervical spine 20 years after whiplash injury, and to examine the relationships between changes in the cervical spine on MRI and changes in related clinical symptoms.
Methods:
Eighty-one subjects finally participated in this study (follow-up rate 16%). The mean follow-up duration was 21.7 years. All subjects filled out a questionnaire about their clinical symptoms. The MRI findings were assessed using numerical grading system applied in the original study. Statistic analyses were used to investigate whether the progression of each MRI finding was associated with the severity of neck pain, stiff shoulders, dizziness and tinnitus.
Results:
All subjects had complained of some clinical symptoms in the original study: 71 had neck pain, 53 stiff shoulders, and others. In the present study, 66 subjects (81.5%) complained of some clinical symptoms: 57 had stiff shoulders, 20 neck pain, and others. The progression of degeneration on MRI was observed in 95% of the subjects, with C4/5 and 5/6 being the most frequently involved levels. Changes in the severity of neck pain, stiff shoulders, dizziness and tinnitus over 20 years were not significantly associated with the progression of degenerative changes in the cervical spine on MRI.
Conclusions:
Twenty years after whiplash injury, 95% of the subjects showed a progression of degeneration in the cervical spine. The progression of the intervertebral disc degeneration in the cervical spine on MRI after whiplash injury was not significantly associated with changes in the severity of related clinical symptoms, indicating that the degenerative changes on MRI may reflect the physiological aging process rather than post-traumatic sequelae.
Forty patients with a whiplash injury who had been reviewed previously 2 and 10 years after injury were assessed again after a mean of 15.5 years by physical examination, pain and psychometric testing.
Twenty-eight (70%) continued to complain of symptoms referable to the original accident. Neck pain was the commonest, but low-back pain was present in half. Women and older patients had a worse outcome. Radiating pain was more common in those with severe symptoms.
Evidence of psychological disturbance was seen in 52% of patients with symptoms. Between 10 and 15 years after the accident 18% of the patients had improved whereas 28% had deteriorated.
Background:
Whiplash Associated Disorders (WAD) is a biopsychosocial problem, education may be an essential part in the treatment and the prevention of chronic WAD. However, it is still unclear which type of educative intervention has already been used in WAD patients and how effective such interventions are.
Objective:
To examine the effectiveness of a cognitive behavioral exercises approach (CBEA) for self-training of the neck relative to usual care in individuals with WAD in acute phase.
Methods:
Forty-one patients, 65.9% female (mean ± SD age: 41 ± 11 years), with WAD were recruited immediately after the accident (within 48 hours) and assigned according to patient choice to receive a CBEA self-training of the neck or usual care for 15 days. The primary outcome measure was pain intensity and disability as measured with the Neck Disability Index (NDI). Secondary outcome measures included the presence of headaches, dizziness, nausea, and difficulties with concentration and memory. Measurements were taken at pre-treatment, 2 weeks post-treatment and 4- and 12- weeks after the injury.
Results:
Patients receiving the CBEA intervention experienced a greater reduction in pain as compared to those receiving the usual care at the end as well as 4 and 12 weeks after the intervention (P< 0.001), for the Neck Disability Index (NDI) decreased more in the CBEA than controls over the 15 days and (F[3.0]= 552.383; P= 0.001), and in both groups at all follow-up periods (all, P= 0.001).
Conclusions:
This quasi-experimental clinical trial provides evidence that a CBEA for self-training of the neck may be more beneficial in treating pain than usual care in patients with WAD. However, the CBEA had limited value in improving NDI. Future studies should include several therapists, a measure of a long-term outcomes and randomize patients to groups.
Study Design
Secondary analysis of a prospective cohort study with cross-sectional and longitudinal analyses.
Background
The clinical importance of a history of whiplash-associated disorder (WAD) in people with neck pain remains uncertain.
Objective
To compare people with WAD to people with nonspecific neck pain, in terms of their baseline characteristics and pain and disability outcomes over 1 year.
Methods
Consecutive patients with neck pain who presented to a secondary-care spine center answered a comprehensive self-report questionnaire and underwent a physical examination. Patients were classified into a group of either those with WAD or those with nonspecific neck pain. We compared the outcomes of baseline characteristics of the 2 groups, as well as pain intensity and activity limitation at follow-ups of 6 and 12 months.
Results
A total of 2578 participants were included in the study. Of these, 488 (19%) were classified as having WAD. At presentation, patients with WAD were statistically different from patients without WAD for almost all characteristics investigated. While most differences were small (1.1 points on an 11-point pain-rating scale and 11 percentage points on the Neck Disability Index), others, including the presence of dizziness and memory difficulties, were substantial. The between-group differences in pain and disability increased significantly (P<.001) over 12 months. At 12-month follow-up, the patients with WAD had on average approximately 2 points more pain and 17 percentage points more disability than those with nonspecific neck pain.
Conclusion
People referred to secondary care with WAD typically had more self-reported pain and disability and experienced worse outcomes than those with nonspecific neck pain. Caution is required when interpreting the longitudinal outcomes due to lower-than-optimal follow-up rates.
Level of Evidence
Prognosis, level 2. J Orthop Sports Phys Ther 2016;46(10):894–901. Epub 3 Sep 2016. doi:10.2519/jospt.2016.6588
Some people believe in cervicogenic headaches, others do not - there has been exaggeration on both sides. In the past 10 years the author studied 191 patients for evaluation by a medical expert. 104 of the patients were represented by a lawyer and 26 more were sent by court. 63 of the 191 patients were male, 128 female, so about 2 out of 3 were female. The average age of the men was 41.8 years (24-66) and of the women 37.5 (20-68). All were victims of a road accident. 129 had suffered a rear-end collision, 33 a frontal collision and 27 another type of road accident with whiplash mechanism, but without head trauma. The time elapsed since the accident was on average 4.23 years (1 to 26 years). The author presents the results of a retrospective study of these patients. 174 of the 191 suffered a new headache after the accident. This means that 91% of the whiplash victims with long-standing health problems had a new type of headache after their accident. The great majority (91%) still suffered from headaches in addition to the neck pain and other typical symptoms of whiplash injury. In 71% of those suffering from a new type of headache, the headache was already present the first day after the accident. The headache mostly irradiated from the neck to the frontal and retroorbital region, either bilaterally or mainly on one side. 124 of these 174 persons had their first headache immediately or not later than one day after the accident, 2 in the course of the first week, 9 in the course of one month following the accident and in 39 this information was not available. The characteristics of the pain, their development with time and the treatments applied are presented. Some speculations about the pathophysiology of this type of headache are added.
Background
Chronic whiplash-associated disorders (WADs) are often associated with social functioning problems and decreased ability to perform previous activities. This may lead to decreased life satisfaction, which is insufficiently studied in the context of whiplash injuries. Symptoms included in chronic WAD are similar to symptoms frequently reported by persons who have sustained mild traumatic brain injury (MTBI)/concussion. In cases of MTBI, the severity and number of symptoms have been suggested to have a diagnostic value. The corresponding importance of symptoms in chronic WAD has not been documented. Most studies of whiplash injuries have focused on neck pain because this is the dominant complaint, while other symptoms are less studied. The frequency of long-term symptoms after whiplash injuries seems to vary. It is difficult to compare the long-term outcome since the follow-up after whiplash injury in most studies has been rather short. Therefore, the primary aim of this investigation was to study neck pain and other symptoms, disability, and life satisfaction five years after whiplash injury in a defined population and geographical area.
Methods
The study was carried out at a public hospital in northern Sweden and was a cross-sectional survey of patients five years after the injury event in a cohort of whiplash-injured patients. Five years after the emergency department visit, 186 persons aged 18–64 answered questionnaires on symptoms (Rivermead Post-Concussion Symptoms Questionnaire, RPQ), disabilities (Rivermead Head Injury Follow Up Questionnaire, RHFUQ), and life satisfaction (LiSat-11). The answers were compared to those of a comparison cohort.
Results
The most common symptoms five years after whiplash injury were fatigue (41%), poor memory (39%), and headache (37%). Inability to sustain previous workload (44%) and fatigue at work (43%) were frequently reported disabilities. Only 39% were satisfied with their somatic health and 60% with their psychological health. Compared with healthy controls, the whiplash injured exhibited more symptoms and had lower life satisfaction. Women reported significantly higher pain intensity than men. Few significant differences between women and men regarding the other parameters were found.
Conclusions
This study shows that five years after a whiplash injury, patients reported symptoms that are typical of mild traumatic brain injury. Further, this study emphasizes the possibility of screening patients with chronic WAD for these symptoms as a complement to the assessment.
Implications
Untreated symptoms may negatively affect the outcome of pain rehabilitation. This implies that it might be clinically meaningful to quantify symptoms earlier in the rehabilitation process
Objectives: To examine the rate of recovery in groups of acute whiplash injury patients subjected to two different treatments, an activity program, or collar use.
Methods: A prospective randomized study of 97 consecutive accident victims of rear-end collisions was carried out utilizing a control group of 50 healthy, age and sex-matched subjects. Symptoms recorded included presence and intensity of neck pain, neck stiffness, headache, shoulder pain, arm pain, and neck range of motion at 1, 2, 3, 6, and 12 weeks. There were 47 patients in the active therapy group [group 1], receiving active and passive mobilization in combination with postural exercises and advice over three weeks. The other 50 accident victims [CT] had a collar only for three weeks.
Results: At three weeks, group 1 [active therapy] had significantly less pain and improved neck range of motion than CT [collar]. Symptom prevalence was no different at six weeks between group 1 and healthy controls. At 12 weeks, CT did not differ from healthy controls in these measures.
Conclusion: The study confirms that active therapy, compared to use of a collar and rest results in a significant difference in rate of recovery. The Quebec Task Force recommendation for active therapy and avoidance of collars appears justified. It would also appear that in Germany, the natural history of the acute whiplash injury shows recovery in weeks.
Objectives: To describe pain syndromes among individuals involved in rear-end motor vehicle collisions [MVCs] for up to two years post-injury. To describe rear-end MVCs by: characteristics of individuals, vehicles, and circumstances surrounding collisions. Methods: Between 1 October 1995 and 31 March 1998, 446 adults involved in rear-end MVCs presented to the emergency departments serving Kingston, Ontario, Canada. Eligible subjects [N = 380] were contacted by telephone following the collisions then at 1, 2, 3, 6, 9, 12, 18 and 24 months post-MVC. Data were collected regarding: symptoms, treatments, work and leisure activities, the collision, and compensation sought and/or received. Results: Ninety-three percent of eligible subjects participated in the study. Sixty-one percent experienced whiplash associated disorder [WAD] [with neck pain] of important severity and frequency following the collision. This declined to 37%, 35%, 34% and 36% at 3, 6, 12 and 24 months post-injury. Common associated symptoms accompanying WAD at six months included: low back pain [44%], neck stiffness [44%], headaches [43%], upper extremity numbness/weakness [26%], and visual complaints [14%]. Sixty percent missed less than one week of work after the collision. At six months, 36% continued to modify their work activities and 35% their leisure activities. Many of the collisions [46%] occurred at an intersection with the majority of vehicles [77%] stopped when hit from behind. The majority of the sample was female [63%] mean age 37 years. Few persons [7.7%] sought financial compensation, and none received any for pain and suffering. Conclusions: This study provides new data about factors associated with WAD following rear-end collisions. Substantial proportions were affected for up to two years post-injury. Repercussions of WAD are reflected in the actual number of individuals with persistent pain, and in the complex array of associated symptoms, treatments sought, and impact on work and leisure activities. These findings exist in an environment where compensation is infrequent.
Somatic and mental symptoms in 22 patients (16 women and 6 men) 22–73 months after a whiplash injury are described. The results
of the present study are compared with the corresponding results of a previous study on the same patients. According to the
Quebec Classification System, the whiplash injuries of 15 patients were classified as grade 2 and those of 7 patients as grade
3. Pain intensity was evaluated by means of a visual analogue scale and muscular tenderness was assessed by pressure algometry.
Algometry was also used to measure the pain tolerance level. The Mood Adjective Check List was used as a measure of mental
well-being. During the 2 years that had passed since the previous study, the patients had improved regarding pain intensity,
pain tolerance level and mental well-being. The results show that patients with prolonged disability after a whiplash injury
can improve even after a long time.
The objective of this study is to determine whether independent associations exist between a history of neck injury related to a motor vehicle collision and: (1) graded neck pain in the past 6 months; (2) headaches in the past 6 months and; (3) depressive symptomatology during the past week. We used data from the Saskatchewan Health and Back Pain Survey, a population-based cross-sectional survey mailed to a stratified random sample of 2184 Saskatchewan adults aged 20–69 years. Fifty-five percent of the eligible population participated. The exposure was collected by asking subjects whether they had ever injured their neck in a motor vehicle collision. The outcomes: 6-month prevalence of graded neck pain, 6-month prevalence headache and depressive symptomatology during the past week were measured with valid and reliable questionnaires. Sixteen percent of the study sample reported a lifetime history of neck injury in a traffic collision. The association between neck injury and the outcomes was determined from polytomous and binary multivariate logistic regression with adjustment for age, gender and other covariates. A history of neck injury was positively associated with low intensity/low disability neck pain (OR=2.81; 95% CI 1.81–4.37), positively associated with high intensity/low disability neck pain (OR=4.46; 95% CI 2.49–4.99) and with disabling neck pain (OR=3.30; 95% CI 1.48–7.39). Similarly, we found a positive association between a history of neck injury in a motor vehicle collision and headaches that moderately/severely impact on one’s health (OR=2.09; 95% CI 1.27–3.44). No association was found between neck injury and depressive symptomatology (OR=0.84; 95% CI 0.50–1.40). Our cross-sectional analysis suggests that neck pain and severe headaches are more prevalent in individuals with a history of neck injury from a car collision. However, the results should not be used to infer a causal relationship between whiplash and chronic neck pain and headaches.
We have reviewed 22 patients at a mean of 30 years (28 to 31) after a whiplash injury. A complete recovery had been made in ten (45.5%) while one continued to describe severe symptoms. Persistent disability was associated with psychological distress but both improved in the period between 15 and 30 years after injury. After 30 years, ten patients (45.5%) were more disabled by knee than by neck pain.
To estimate the prevalence of jaw symptoms and signs during the first year after a neck sprain in a car collision. Further, to determine their relationships to the localisation and grade of the initial neck symptoms and signs, headache, post-traumatic stress and crash characteristics.
One hundred and forty-six adult subjects and crash characteristics were prospectively investigated in an in-depth study during 1997-2001. Head, neck, and jaw symptoms and signs were recorded within 5 weeks and after 1 year. Acute post-traumatic stress was estimated with the Impact of Event Scale-Revised (IES-R).
Jaw symptoms were initially reported by three men (5%) and three women (4%), and subsequently developed in eight women (10%) during the following year. Jaw signs were noted initially in 53 subjects (37%) and in 28 subjects (24%) after 1 year, without difference between sexes, and more often after low-speed impacts. Headache in females, cranial cervical symptoms, pronounced neck problems, post-traumatic stress and whiplash-associated disorders (WAD) grade II-III after rear-end impacts were related to jaw signs during the acute phase. After 1 year, jaw signs were related to residual neck problems, headache and post-traumatic stress.
Jaw symptoms are seldom reported during the acute phase after a whiplash trauma. Women more often than men develop jaw symptoms during the first year. Jaw symptoms and signs may develop also after low-speed impacts, especially after rear-end collisions. Jaw symptoms and signs should be observed after whiplash trauma, especially in those with headache, pronounced neck problems, cranial neck symptoms and post-traumatic stress.
The objective of this study is to assess the long-term outcome and natural history of a cohort of patients with whiplash injury regarding the development of fibromyalgia. Of the 153 patients who were admitted to the emergency room after whiplash injury in 2004, 126 were reassessed 3 years later. Also, 33 of 53 patients from the original control group of hospitalized patients with fractures were reevaluated. Patients were interviewed by phone and by written forms using a detailed questionnaire. Patients who complained of musculoskeletal symptoms were invited and examined. The study group included 68 men and 58 women, with a mean age of 50.1 ± 9.7. The control group included 19 men and 14 women with a mean age of 44.2 ± 10.3. Follow-up period did not differ significantly between the groups 38.3 ± 2.3 vs. 36.4 ± 4.2 months. At the end of the follow-up period, three patients in the study group compared with one patient in the control group were diagnosed as having fibromyalgia; all of them were women. The rate of new onset widespread pain increased with time in both groups. Symptoms of dizziness, headaches, fatigue and sleep disturbances improved, as well as the quality of life (QOL) and the Fibromyalgia Impact Questionnaire (FIQ) scores. Insurance claims continued to be more prevalent in the control group. The results of this extended follow-up study confirm previous short-term results showing that whiplash injury and road accident trauma are not associated with an increased risk of fibromyalgia.
Despite a large number of rear-end collisions on the road and a high frequency of whiplash injuries reported, the mechanism of whiplash injuries is not completely understood. One of the reasons is that the injury is not necessarily accompanied by obvious tissue damage detectable by X-ray or MRI. An extensive series of biomechanics studies, including injury epidemiology, neck kinematics, facet capsule ligament mechanics, injury mechanisms and injury criteria, were undertaken to help elucidate these whiplash injury mechanisms and gain a better understanding of cervical facet pain. These studies provide the following evidences to help explain the mechanisms of the whiplash injury: (1) Whiplash injuries are generally considered to be a soft tissue injury of the neck with symptoms such as neck pain and stiffness, shoulder weakness, dizziness, headache and memory loss, etc. (2) Based on kinematical studies on the cadaver and volunteers, there are three distinct periods that have the potential to cause injury to the neck. In the first stage, flexural deformation of the neck is observed along with a loss of cervical lordosis; in the second stage, the cervical spine assumes an S-shaped curve as the lower vertebrae begin to extend and gradually cause the upper vertebrae to extend; during the final stage, the entire neck is extended due to the extension moments at both ends. (3) The in vivo environment afforded by rodent models of injury offers particular utility for linking mechanics, nociception and behavioral outcomes. Experimental findings have examined strains across the facet joint as a mechanism of whiplash injury, and suggested a capsular strain threshold or a vertebral distraction threshold for whiplash-related injury, potentially producing neck pain. (4) Injuries to the facet capsule region of the neck are a major source of post-crash pain. There are several hypotheses on how whiplash-associated injury may occur and three of these injuries are related to strains within the facet capsule connected with events early in the impact. (5) There are several possible injury criteria to correlate with the duration of symptoms during reconstructions of actual crashes. These results form the biomechanical basis for a hypothesis that the facet joint capsule is a source of neck pain and that the pain may arise from large strains in the joint capsule that will cause pain receptors to fire.
Most whiplash patients eventually recover, although some are left with ongoing pain and impairment. Why some develop long-term symptoms after whiplash, whereas others do not, is largely unknown. One explanation blames the cultural expectations of the population wherein the injury occurred, engendering the moniker whiplash culture. The purpose of this review was to locate and discuss studies that were used as a basis for developing the whiplash culture concept and to evaluate its plausibility.
The PubMed database was searched using combinations of the terms whiplash culture, whiplash OR WAD, and chronic OR late OR long term. Search dates spanned from 1950 to June 2008. Filters were set to only retrieve English-language citations. Articles that dealt with the whiplash culture were selected and examined to determine which studies had been used to create the concept.
Nineteen articles discussed the cultural aspects of whiplash and were explored to determine which were used as a basis for the whiplash culture. Eight studies were found that met this final criterion.
There are many unanswered questions about the basis of chronic whiplash, and the notion of a whiplash culture is controversial. Chronic whiplash symptoms are surely not caused entirely by cultural issues, yet they are probably not entirely physical. Presumably, a tissue injury component exists in most chronic whiplash-associated disorder victims that becomes aggravated in those who are susceptible to biopsychosocial factors. As with many other controversial health care topics, the answer to the debate probably lies somewhere in the middle.
We identified clinical, demographic and psychological predictive factors that may contribute to the development of chronic headache associated with mild to moderate whiplash injury [Quebec Task Force (QTF) ≤ II] and determined the incidence of this chronic pain state. Patients were recruited prospectively from six participating accident and emergency departments. While 4.6% of patients developed chronic headache attributed to whiplash injury according to the International Classification of Headache Disorders, 2nd edn criteria, 15.2% of patients complained about headache lasting > 42 days (QTF criteria). Predictive factors were pre-existing facial pain [odds ratio (OR) 9.7, 95% confidence interval (CI) 2.1, 10.4; P = 0.017], lack of confidence to recover completely (OR 5.5, 95% CI 2.0, 13.2; P = 0.005), sore throat (OR 5.0, 95% CI 1.5, 8.9; P = 0.013), medication overuse (OR 4.2, 95% CI 1.4, 12.3; P = 0.009), high Neck Disability Index (OR 4.0, 95% CI 1.3, 12.6; P = 0.019), hopelessness/anxiety (OR 3.8, 95% CI 1.3, 8.7; P = 0.024), and depression (OR 3.3, 95% CI 1.2, 9.4; P = 0.024). The lack of a control group limits the conclusions that can be drawn from this study. Identified predictors closely resemble those found in chronic primary headache disorders.
This review discusses the causes, outcome and prevention of whiplash injury, which costs the economy of the United Kingdom approximately pound 3.64 billion per annum. Most cases occur as the result of rear-end vehicle collisions at speeds of less than 14 mph. Patients present with neck pain and stiffness, occipital headache, thoracolumbar back pain and upper-limb pain and paraesthesia. Over 66% make a full recovery and 2% are permanently disabled. The outcome can be predicted in 70% after three months.
Best evidence synthesis.
To undertake a best evidence synthesis on the burden and determinants of whiplash-associated disorders (WAD) after traffic collisions.
Previous best evidence synthesis on WAD has noted a lack of evidence regarding incidence of and risk factors for WAD. Therefore there was a warrant of a reanalyze of this body of research.
A systematic search of Medline was conducted. The reviewers looked for studies on neck pain and its associated disorders published 1980-2006. Each relevant study was independently and critically reviewed by rotating pairs of reviewers. Data from studies judged to have acceptable internal validity (scientifically admissible) were abstracted into evidence tables, and provide the body of the best evidence synthesis.
The authors found 32 scientifically admissible studies related to the burden and determinants of WAD. In the Western world, visits to emergency rooms due to WAD have increased over the past 30 years. The annual cumulative incidence of WAD differed substantially between countries. They found that occupant seat position and collision impact direction were associated with WAD in one study. Eliminating insurance payments for pain and suffering were associated with a lower incidence of WAD injury claims in one study. Younger ages and being a female were both associated with filing claims or seeking care for WAD, although the evidence is not consistent. Preliminary evidence suggested that headrests/car seats, aimed to limiting head extension during rear-end collisions had a preventive effect on reporting WAD, especially in females.
WAD after traffic collisions affects many people. Despite many years of research, the evidence regarding risk factors for WAD is sparse but seems to include personal, societal, and environmental factors. More research including, well-defined studies with accurate denominators for calculating risk, and better consideration of confounding factors, are needed.
Twenty one unselected patients with an acute whiplash injury of the neck had neurological and neuropsychological assessment, cervical x rays, EEG, BAEP, MRI, and an otoneurological examination within two weeks of the injury. Subjectively, 13 patients reported concentration deficits, 18 reported sleep disturbances, 9 had symptoms of depression, and 7 female patients told of menstrual irregularities. Neuropsychological examination revealed significantly lower performance in tests related to attention and concentration compared to sex, age and educational matched control subjects. Otoneurological examination showed abnormalities in 9 of 17 whiplash subjects. EEG showed questionable changes in 8 of 18 recordings. MRI and BAEP were normal in all patients. Repeat neuropsychological testing in 15 patients at three months showed that attention deficits had improved but were still shown in 12 of 14 and the concentration deficits in 8 of 13 patients. At one year all patients had returned to work, 16 to full and 5 to part time employment. In 4, cognitive dysfunction remained the only significant problem. These findings are discussed as being compatible with possible damage to basal frontal and upper brain stem structures after whiplash injury of the neck.
Ninety-three cases with a car-accident soft-tissue injury of the cervical spine were studied prospectively. Neck pain and stiffness were the main initial symptoms, while 4 cases had abnormal neurologic signs. At follow-up, on an average 2 years after the accident, 42 percent had recovered completely, 15 percent had minor discomfort, and 43 percent had discomfort sufficient to interfere with their capacity for work. The statistical analysis of 17 factors, including acute symptoms and physical findings, as well as the forces and directions of impact, head rests, radiographs, length, and sex, did not reveal any factor of prognostic importance.
Injury of the neck may result when a motor vehicle is run into from behind; such injury is frequently the cause of prolonged disability and litigation. We report a series of 61 patients with these injuries. A classification, based upon the presenting symptoms and physical signs has been evolved. This classification is shown to be a reliable basis for formulating a prognosis. Factors which adversely affect prognosis include the presence of objective neurological signs, stiffness of the neck, muscle spasm, and pre-existing degenerative spondylosis.
A condition commonly seen after motor vehicle accidents, the Late Whiplash Syndrome, which is defined as a collection of symptoms and disabilities seen more than six months after a neck injury occurring in a motor vehicle accident, is examined in a series of 300 cases. The author suggests that the development of the Late Whiplash Syndrome, some of whose characteristics are viewed as illness and some as illness behavior, depends on social variables.
The differential distribution in Western countries and in Singapore is related to sanctions against entry into the sick role associated with this type of injury which are present in countries such as Singapore. Conversely, motor vehicle injury is legitimized in Western Countries such as Australia as an historical overview shows.
The author's model of the Late Whiplash Syndrome lends itself to generalizations about the development of social illness in different cultures.
With the increased incidence of whiplash injury following the introduction of compulsory car seat belts, a large number of reports have dealt with the aftermath of this condition. Previous studies, however, focused on somatic symptoms on the one hand or considered only psychological or neuropsychological variables on the other hand, often in loosely defined or selected groups of patients. No study so far has analyzed the long-term outcome in a nonselected group of patients using a clear injury definition considering patient history; somatic, radiologic, and neuropsychological findings; and features of the injury mechanisms assessed soon after trauma and during follow-up. the present investigation was designed to assess these combined factors. According to a strict definition of whiplash injury, we assessed a consecutive nonselected sample of 117 patients with recent injury who had similar sociocultural and educational backgrounds. The patients had been in automobile crashes and were all equally covered by accident insurance according to the country-wide scheme. Initial examination was performed 7.2 +/- 4.2 days after trauma, and follow-up examinations 3, 6, 12, and 24 months later. At baseline, features of injury mechanism, subjective complaints, and different aspects of patient history were documented and cervical spine X rays performed. At all examinations patients underwent neurologic examination and cognitive and psychosocial factor assessment. At 2 years, patients were divided into symptomatic and asymptomatic groups and then compared with regard to the initial findings. In addition, symptomatic patients who were disabled at the 2-year follow-up examination and symptomatic patients not disabled (that is, they were able to work at the pretraumatic level) were compared regarding initial and 2-year findings. At 2 years, 18% of patients still had injury-related symptoms. With regard to baseline findings the following significant differences were found: Symptomatic patients were older, had higher incidence of rotated or inclined head position at the time of impact, had higher prevalence of pretraumatic headache, showed higher intensity of initial neck pain and headache, complained of a greater number of symptoms, had a higher incidence of symptoms of radicular deficit and higher average scores on a multiple symptom analysis, and displayed more degenerative signs (osteoarthrosis) on X ray. In addition, symptomatic patients scored higher with regard to impaired well-being and performed worse on tasks of attentional functioning and showed more concern with regard to long-term suffering and disability.(ABSTRACT TRUNCATED AT 400 WORDS)
39 consecutive cases of whiplash injury of the neck were examined clinically and with MRI at a mean of 11 days after trauma. 26 of these showed changes on MRI with disc lesions in 25, 10 of which were classified as disc herniations, and a muscle lesion in 1 case. All had neck pain or headache. 29 cases had neurological deficits, mostly sensibility disturbances. 22 of the 26 cases with pathologic MRI findings had neurological signs, as had 7 of the 10 cases with disc herniation. The relationship between the MRI findings and the clinical symptoms and signs was poor.
To analyse the significance of the interplay between somatic and psychosocial factors in influencing the course of recovery a non-selected well defined group of 117 whiplash patients was investigated. Initial examination was performed, on average, 7.2 +/- 4.2 days after trauma and follow-ups were carried out at 3, 6 and 12 months. At the initial investigation all patients were given a neurological examination, cognitive and psychosocial factor assessment and cervical spine X-rays. At each follow-up stepwise regression was performed to evaluate the relationship between initial findings and the course of recovery. Fifty-one (44%), 36 (31%) and 28 (24%) patients were symptomatic at 3, 6 and 12 months respectively. Poor improvement at all examinations was significantly correlated with factors associated with severity of injury such as initial symptoms of radicular irritation and intensity of neck pain. Moreover, results indicate that poor recovery is related to severity of injury in addition to some pre-traumatic factors (previous history of head trauma and headache) and initial injury-related reaction (i.e. sleep disturbances, reduced speed of information processing and nervousness). However, psychosocial factors did not prove predictive at any follow-up examination. These results indicate that symptoms suggesting a more severe neck injury appear to be particularly related to delayed recovery from common whiplash. Moreover these results may be of value in the objective evaluation of potentially difficult claims for compensation, which may in some cases be falsely based.
The relationship between psychosocial stress, cognitive performance and disability was assessed in 97 randomly selected common whiplash patients. Patients were investigated early after injury (mean 7.2 days, SD = 3.8) and again at 6 months. Assessment included different aspects of psychosocial stress, negative affectivity, personality traits and attentional functioning. At 6 months six patients (7%) showed partial or complete disability (disabled group) while 91 patients went back to work at pre-injury levels (non-disabled group). However, 26 patients from the latter group at 6 months were still symptomatic. The disabled and non-disabled groups did not differ with respect to psychosocial stress, negative affectivity and personality traits as assessed at baseline. At 6 months no significant differences were found between the disabled group and 26 symptomatic patients from the non-disabled group with respect to any of the assessed factors. The disabled group showed a combination of the following variables as assessed at baseline: greater age, initial neck pain intensity, initial back pain, blurred vision, and anxiety but less dizziness, sensitivity to noise and neurotic or behavioural problems in childhood.
In Lithuania, few car drivers and passengers are covered by insurance and there is little awareness among the general public about the potentially disabling consequences of a whiplash injury. We took this opportunity to study the natural course of head and neck symptoms after rear-end car collisions.
In a retrospective questionnaire-based cohort study, 202 individuals (157 men; 45 women) were identified from the records of the traffic police department in Kaunas, Lithuania. These individuals were interviewed 1-3 years after experiencing a rear-end car collision. Neck pain, headache, subjective cognitive dysfunction, psychological disorders, and low back pain in this group were compared with the same complaints in a sex-matched and age-matched control group of uninjured individuals selected randomly from the population register of the same geographic area.
Neck pain was reported by 71 (35% [95% CI 29-42]) accident victims and 67 (33% [27-40]) controls. Headache was reported by 107 (53% [46-60]) accident victims and 100 (50% [42-57]) controls. Chronic neck pain and chronic headache (more than 7 days per month) were also reported in similar proportions (17 [8.4%; 5-13] vs 14 [6.9%; 4-12] and 19 [9.4%; 6-15] vs 12 [5.9%; 3-10]) by the two groups. Of those who reported chronic neck pain or daily headache after the accident, substantial proportions had had similar symptoms before the accident (7/17 for chronic neck pain; 10/12 for daily headache). There was no significant difference found. No one in the study group had disabling or persistent symptoms as a result of the car accident. There was no relation between the impact severity and degree of pain. A family history of neck pain was the most important risk factor for current neck symptoms in logistic regression analyses.
Our results suggest that chronic symptoms were not usually caused by the car accident. Expectation of disability, a family history, and attribution of pre-existing symptoms to the trauma may be more important determinants for the evolution of the late whiplash syndrome.
To evaluate the findings from magnetic resonance (MR) imaging of the cervical spine and brain after acute whiplash injury.
Within 3 weeks of trauma, 100 patients underwent MR imaging for evaluation of the cervical spine and the brain. In addition, plain radiographs were obtained, including functional images of the cervical spine.
Only one patient had an abnormality on the MR image that was related to trauma (ie, prevertebral edema). In 17 patients, functional images showed a kyphotic angle, but no evidence of soft-tissue injury was seen on MR images.
There is no role for MR imaging in the routine work-up of patients with acute whiplash injury who have normal plain radiographic findings and no evidence of a neurologic deficit. A kyphotic angle seen on functional images of the cervical spine should not be assumed to indicate soft-tissue injury and is most likely attributable to a compensating mechanism of hypermobility at a level of the spine above that at which hypomobility occurs, which is probably the result of a muscle spasm.
Psychological factors have been alleged to be important in the course and outcome of 'whiplash' neck injury but there is little quantitative evidence. This study uses quantitative methods involving a prospective interview assessment to describe psychological and quality of life predictors, and 3 and 12 month outcome. Consecutive attenders to the Accident and Emergency department of a teaching district hospital with a clinical diagnosis of 'whiplash' neck injury were included and there were follow-up interviews at home. Neck symptoms were recorded, and there was a standard mental-state interview with added questions about post-traumatic symptoms and a semi-structured interview for disability and consequences for quality of life. There was a wide individual variation in course and outcome; the majority of subjects complained of persistent neck symptoms and a sizeable minority reported specific post-traumatic psychological symptoms (intrusive memory, phobic travel anxiety), similar to those described by patients suffering multiple injuries. Social impairment, including effects on travel, were considerable in one-quarter. Reports of persistent neck symptoms were not associated with any baseline psychological variables or with compensation proceedings; psychological factors appeared to be more important in determining the extent of social impairment. We conclude that travel, social and psychological morbidity is substantially greater than previously recognized.
The acute symptoms after whiplash traumas can be explained by the neck sprain, but the pathogenesis of the "late whiplash syndrome" and the reason why only some people have persistent symptoms more than 6 months is still unknown.
Thirty-four consecutive cases of whiplash injury were examined clinically three times; within 14 days, after 1 month and finally 7 months postinjury. In addition, MRI of the brain and the cervical spine, neuropsychological tests and motor evoked potentials (MEP) were done one month postinjury and repeated after 6 months, if abnormalities were found.
The total recovery rate (asymptomatic patients) was 29% after 7 months. MRI was repeated in 6 patients. The correlation between MRI and the clinical findings was poor. Cognitive dysfunction as a symptom of brain injury was not found. Stress at the same time predicted more symptoms at follow-up. All MEP examinations were normal.
In this study, long-lasting distress and poor outcome were more related to the occurrence of stressful life events than to clinical and paraclinical findings.
The relationships between personality and psychiatric symptoms and long-lasting physical symptoms were assessed in 88 neck sprain patients injured in car accidents. The Millon Clinical Multiaxial Inventory (MCMI-I) was completed at time of occurrence (intake) and 6 months after the injury. The neck sprain patients were divided into three subgroups according to symptoms 6 months after the accident. In addition, the total neck sprain group was compared with three other subject groups. The results indicated that the three neck sprain subgroups did not differ on the MCMI-I neither at intake nor 6 months later. The total neck sprain patients group was significantly different from patients with major depression on all scales of the MCMI-I, but not significantly different compared to patients with localized musculoskeletal pain. Compared to a group of health personnel, there were only a few significant differences. The study does not support the view that premorbid personality traits can predict outcome for neck sprain patients.
Headache is frequently reported as a chronic complaint after whiplash traumas. Criteria have been presented, but it has not been validated whether any specific headache type emerges after a trauma with whiplash mechanism. In a questionnaire-based historical cohort design, 202 adult Lithuanian individuals were interviewed 1-3 years after experiencing a rear-end car collision. The questionnaire was designed so that a diagnosis of migraine and tension-type headache in accordance with the International Headache Society criteria could be made. "Possible cervicogenic headache" was diagnosed according to Sjaastad et al.'s minimal criteria. The diagnostic panorama in those with traumas was compared with that of an age- and sex-matched control group. The introductory questions did not reveal differences in headache frequencies between the traumatized and control groups (p = 0.60). The prevalence of migraine and tension-type headache (both episodic and chronic) was also similar. A higher frequency of possible cervicogenic headache was observed in the traumatized group (10 vs 5), but the difference was not statistically significant (p = 0.28). Sixteen patients in the accident group had headache > 15 days per month, 11 of the 16 had similar complaints before the trauma, while 5 had worsened headache as compared to (the recollected headache) before the trauma. None of the patients with possible cervicogenic headache reported increased headache after the accident. Accordingly, the present results obtained outside the medico-legal context do not confirm that a specific headache pattern emerges 1-3 years after a rear-end car collision.
An earlier pilot study suggested that the late whiplash syndrome is uncommon in Greece. The purpose of the present study is to extend the evaluation to a larger sample, and include the prevalence of specific symptoms in the evaluation.
In a prospective, cohort study, a total of 180 accident victims were consecutively recruited following Emergency ward presentation. A standard questionnaire asked about neck pain, headache, shoulder pain, limb numbness or pain, and dizziness. Accident victims were followed for 6 months.
In the initial 4 weeks after the accident, accident victims reported neck pain, headache, shoulder pain, arm numbness or pain, and dizziness, but at 4 weeks more than 90% had recovered from these, the remainder of the subjects having minor symptoms (not requiring therapy), and returning to their pre-accident state of health (which included minor symptoms). There were no cases of chronic disability.
In Greece, symptoms after an acute whiplash injury are self-limiting, brief, and do not appear to evolve into the so-called late whiplash syndrome.
The incidence and prognosis of whiplash injury from motor vehicle collisions may be related to eligibility for compensation for pain and suffering. On January 1, 1995, the tort-compensation system for traffic injuries, which included payments for pain and suffering, in Saskatchewan, Canada, was changed to a no-fault system, which did not include such payments. To determine whether this change was associated with a decrease in claims and improved recovery after whiplash injury, we studied a population-based cohort of persons who filed insurance claims for traffic injuries between July 1, 1994, and December 31, 1995.
Of 9006 potentially eligible claimants, 7462 (83 percent) met our criteria for whiplash injury. The six-month cumulative incidence of claims was 417 per 100,000 persons in the last six months of the tort system, as compared with 302 and 296 per 100,000, respectively, in the first and second six-month periods of the no-fault system. The incidence of claims was higher for women than for men in each period; the incidence decreased by 43 percent for men and by 15 percent for women between the tort period and the two no-fault periods combined. The median time from the date of injury to the closure of a claim decreased from 433 days (95 percent confidence interval, 409 to 457) to 194 days (95 percent confidence interval, 182 to 206) and 203 days (95 percent confidence interval, 193 to 213), respectively. The intensity of neck pain, the level of physical functioning, and the presence or absence of depressive symptoms were strongly associated with the time to claim closure in both systems.
The elimination of compensation for pain and suffering is associated with a decreased incidence and improved prognosis of whiplash injury.