[Show abstract][Hide abstract] ABSTRACT: This study examined whether intracranial neuroimaging abnormalities in those with mild traumatic brain injury (MTBI) (i.e., "complicated" MTBIs) are associated with worse subacute outcomes as measured by cognitive testing, symptom ratings, and/or diffusion tensor imaging (DTI). We hypothesized that (i) as a group, participants with complicated MTBIs would report greater symptoms and have worse neurocognitive outcomes than those with uncomplicated MTBI, and (ii) as a group, participants with complicated MTBIs would show more Diffusion Tensor Imaging (DTI) abnormalities. Participants were 62 adults with MTBIs (31 complicated and 31 uncomplicated) who completed neurocognitive testing, symptom ratings, and DTI on a 3T MRI scanner approximately 6-8 weeks post injury. There were no statistically significant differences between groups on symptom ratings or on a broad range of neuropsychological tests. When comparing the groups using tract-based spatial statistics for DTI, no significant difference was found for axial diffusivity or mean diffusivity. However, several brain regions demonstrated increased radial diffusivity (purported to measure myelin integrity), and decreased fractional anisotropy in the complicated group compared with the uncomplicated group. Finally, when we extended the DTI analysis, using a multivariate atlas based approach, to 32 orthopedic trauma controls (TC), the findings did not reveal significantly more areas of abnormal DTI signal in the complicated vs. uncomplicated groups, although both MTBI groups had a greater number of areas with increased radial diffusivity compared with the trauma controls. This study illustrates that macrostructural neuroimaging changes following MTBI are associated with measurable changes in DTI signal. Of note, however, the division of MTBI into complicated and uncomplicated subtypes did not predict worse clinical outcome at 6-8 weeks post injury.
PLoS ONE 04/2015; 10(4):e0122746. DOI:10.1371/journal.pone.0122746 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives:
We evaluated the public health benefits of traffic laws targeting speeding and drunk drivers (British Columbia, Canada, September 2010).
We studied fatal crashes and ambulance dispatches and hospital admissions for road trauma, using interrupted time series with multiple nonequivalent comparison series. We determined estimates of effect using linear regression models incorporating an autoregressive integrated moving average error term. We used neighboring jurisdictions (Alberta, Saskatchewan, Washington State) as external controls.
In the 2 years after implementation of the new laws, significant decreases occurred in fatal crashes (21.0%; 95% confidence interval [CI]=15.3, 26.4) and in hospital admissions (8.0%; 95% CI=0.6, 14.9) and ambulance calls (7.2%; 95% CI=1.1, 13.0) for road trauma. We found a very large reduction in alcohol-related fatal crashes (52.0%; 95% CI=34.5, 69.5), and the benefits of the new laws are likely primarily the result of a reduction in drinking and driving.
These findings suggest that laws calling for immediate sanctions for dangerous drivers can reduce road trauma and should be supported.
American Journal of Public Health 08/2014; 104(10):e1-e9. DOI:10.2105/AJPH.2014.302068 · 4.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of the study was to disentangle the relative contributions of day-of-injury alcohol intoxication and pre-injury alcohol misuse on outcome from TBI. Participants were 142 patients enrolled from a Level 1 Trauma Center (in Vancouver, Canada) following a traumatic brain injury (TBI; 43 uncomplicated mild TBI and 63 complicated mild-severe TBI) or orthopedic injury [36 trauma controls (TC)]. At 6-8 weeks post-injury, diffusion tensor imaging (DTI) of the whole brain was undertaken using a Phillips 3T scanner. Participants also completed neuropsychological testing, an evaluation of lifetime alcohol consumption (LAC), and had blood alcohol levels (BALs) taken at the time of injury. Participants in the uncomplicated mild TBI and complicated mild-severe TBI groups had higher scores on measures of depression and postconcussion symptoms (d = 0.45-0.83), but not anxiety, compared with the TC group. The complicated mild-severe TBI group had more areas of abnormal white matter on DTI measures (all p < .05; d = 0.54-0.61) than the TC group. There were no difference between groups on all neurocognitive measures. Using hierarchical regression analyses and generalized linear modeling, LAC and BAL did provide a unique contribution toward the prediction of attention and executive functioning abilities; however, the variance accounted for was small. LAC and BAL did not provide a unique and meaningful contribution toward the prediction of self-reported symptoms, DTI measures, or the majority of neurocognitive measures. In this study, BAL and LAC were not predictive of mental health symptoms, postconcussion symptoms, cognition, or white-matter changes at 6-8 weeks following TBI.
[Show abstract][Hide abstract] ABSTRACT: Demographic data in North America, Europe, Asia, Australia and New Zealand suggest a rapid growth in the number of persons over the age of 65 years as the baby boomer generation passes retirement age. As older adults make up an increasing proportion of the population, they are an important consideration when designing future evidence-based traffic safety policies, particularly those that lead to restrictions or cessation of driving. Research has shown that cessation of driving among older drivers can lead to negative emotional consequences such as depression and loss of independence. Older adults who continue to drive tend to do so less frequently than other demographic groups and are more likely to be involved in a road traffic crash, possibly due to what is termed the "low mileage bias". Available research suggests that older driver crash risk estimates based on traditional exposure measures are prone to bias. When annual driving distances are taken in to consideration, older drivers with low driving distances have an increased crash risk, while those with average or high driving distances tend to be safer drivers when compared to other age groups. In addition, older drivers with lower distance driving tend to drive in urban areas which, due to more complex and demanding traffic patterns, tend to be more accident-prone. Failure to control for actual annual driving distances and driving locations among older drivers is referred to as "low mileage bias" in older driver mobility research. It is also important to note that older drivers are more vulnerable to serious injury and death in the event of a traffic crash due to changes in physiology associated with normal ageing. Vision, cognition, and motor functions or skills (e.g., strength, co-ordination, and flexibility) are three key domains required for safe driving. To drive safely, an individual needs to be able to see road signs, road side objects, traffic lights, roadway markings, other vulnerable road users, and other vehicles on the road, among many other cues-all while moving, and under varying light and weather conditions. It is equally important that drivers must have appropriate peripheral vision to monitor objects and movement to identify possible threats in the driving environment. It is, therefore, not surprising that there is agreement among researchers that vision plays a significant role in driving performance. Several age-related processes/conditions impair vision, thus it follows that vision testing of older drivers is an important road safety issue. The components of visual function essential for driving are acuity, static acuity, dynamic acuity, visual fields, visual attention, depth perception, and contrast sensitivity. These indices are typically not fully assessed by licensing agencies. Also, current vision screening regulations and cut-off values required to pass a licensing test vary from country to country. Although there is a clear need to develop evidence-based and validated tools for vision screening for driving, the effectiveness of existing vision screening tools remains unclear. This represents an important and highly warranted initiative to increase road safety worldwide.
To assess the effects of vision screening interventions for older drivers to prevent road traffic injuries and fatalities.
For the update of this review we searched the Cochrane Injuries Group's Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE (OvidSP), Embase (OvidSP), PsycINFO (OvidSP) and ISI Web of Science: (CPCI-S & SSCI). The searches were conducted up to 26 September 2013.
Randomised controlled trials (RCTs) and controlled before and after studies comparing vision screening to non-screening of drivers aged 55 years and older, and which assessed the effect on road traffic crashes, injuries, fatalities and any involvement in traffic law violations.
Two review authors independently screened the reference lists for eligible articles and independently assessed the articles for inclusion against the criteria. If suitable trials had been available, two review authors would have independently extracted data using a standardised extraction form.
No studies were found that met the inclusion criteria for this review.
Most countries require a vision screening test for the renewal of an individual's driver's licence. There is, however, lack of methodologically sound studies to assess the effects of vision screening tests on subsequent motor vehicle crash reduction. There is a need to develop valid and reliable tools of vision screening that can predict driving performance.
[Show abstract][Hide abstract] ABSTRACT: Objectives:
The purpose of this study was to evaluate the rate of, and risk factors for, subsequent impaired driving activity (IDA) in a cohort of injured passengers who were treated for injuries in a Canadian trauma center.
We studied adult passengers who were occupants in vehicles involved in motor vehicle crashes (MVCs) and either included in the British Columbia (BC) trauma registry (January 1, 1992-December 31, 2004) or treated in the emergency department (ED) of Vancouver General Hospital (VGH; January 1, 1999-December 31, 2003). Passengers were linked to their driver's license and hence to their driving record using personal health number and demographic information. Injured passengers were stratified into 3 groups based on their blood alcohol concentration (BAC) at time of ED presentation: group 1: BAC = 0, group 2: 0 < BAC ≤ 17.3 mM (0.08%), group 3: BAC > 17.3 mM (0.08%). Two outcome variables were studied: involvement in a subsequent IDA and time to their first subsequent IDA. IDA was defined as a criminal code conviction for impaired driving, a 24-h or 90-day license suspension for impaired driving, and/or involvement in an MVC where police cited alcohol as a factor. Time to first IDA following the index event among passenger BAC groups was compared with Kaplan-Meier survival analysis. Cox proportional hazards models were employed to examine the effect of various potential risk factors on time to engage in first IDA.
Injured passengers with any BAC at the time of ED visit were more likely to engage in IDA and had their first IDA sooner after the index event than those with zero BAC. Among this cohort of injured passengers, 12.1 percent with BAC = 0, 29.9 percent with 0 < BAC ≤ 17.3 mM (0.08%), and 37.8 percent with a BAC > 17.3 mM (0.08%) engaged in IDA. Compared to passengers with BAC = 0, group 3 passengers and group 2 passengers were 2.06 times and 1.79 times more likely to engage in future IDA. Twenty-five percent of injured passengers engaged their first IDA by 57 and 38 months in groups 2 and 3, respectively. Previous IDA and being male were also significant risk factors for future IDA. Those with a history of IDA before the index event were 2.37 times more likely to engage in subsequent IDA.
Injured alcohol-impaired passengers are at high risk for IDA and should be included in impaired driving prevention programs.
[Show abstract][Hide abstract] ABSTRACT: The magnitude of risk of injury from drinking, based on emergency department (ED) studies, has been found to vary considerably across studies, and the impact of study design on this variation is unknown.
Patients were interviewed regarding drinking within 6 hours prior to the injury or illness event, drinking during the same time the previous week, and usual drinking during the last 30 days. Risk estimates were derived from case-control analysis and from both pair-matched and usual frequency case-crossover analysis.
The odds ratio (OR) based on case-control (2.7; 1.9 to 3.8) was larger than that based on pair-matched case-crossover analysis (1.6; 1.0 to 2.6). The control-crossover estimate suggested the case-crossover estimate was an underestimate of risk, and when this adjustment was applied to the case-crossover estimate, risk of injury increased (OR = 3.2; 1.7 to 6.0). Adjusted case-crossover estimates compared with unadjusted showed the largest proportional increase at 7 or more drinks prior to injury (OR = 7.1; 2.2 to 22.9). The case-crossover estimate based on usual frequency of drinking was substantially larger (OR = 10.7; 8.0 to 14.3) than that based on case-control or pair-matched case-crossover analysis, but less than either when adjusted based on control-crossover usual frequency analysis (OR = 2.2; 1.5 to 3.3).
The data suggest that while risk of injury based on case-control analysis may be biased, control data are important in providing adjustments derived from control-crossover analysis to case-crossover estimates, and are most important at higher levels of consumption prior to the event.
Alcoholism Clinical and Experimental Research 08/2013; 38(1). DOI:10.1111/acer.12217 · 3.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective:
Injured drivers with blood alcohol concentration (BAC) above the legal limit are rarely convicted of impaired driving. One explanation is that police may have difficulty recognizing alcohol intoxication in injured drivers. In this study, we compare police documentation of alcohol involvement with BAC measured on arrival at a hospital. Our objectives were to determine how often police document alcohol involvement in injured drivers with BAC ≥ 0.05 percent and identify factors that influence police documentation of alcohol involvement.
We included injured drivers (1999-2003) who were admitted to a British Columbia trauma center or treated in the Vancouver General Hospital emergency department. We used probabilistic linkage to obtain police collision reports. Police were considered to have indicated alcohol involvement if (1) police documented that alcohol contributed to the crash, (2) the driver received an administrative sanction for impaired driving, or (3) the driver was criminally convicted of impaired driving. The proportion of drivers for whom police indicated alcohol involvement was determined relative to age, gender, BAC levels, crash severity, and crash characteristics. Multivariate logistic regression was used to identify factors independently associated with police indication of alcohol involvement.
Two thousand four hundred and ten injured drivers (73.5% male) were matched to a police report. Overall, 857 (35.6%) drivers tested positive for alcohol (BAC ≥ 0) and 736/857 (85.9%) of alcohol-positive drivers had a BAC ≥ 0.05 percent (the legal limit in British Columbia). Of the 736 drivers with a BAC > 0.05 percent at time of admission, police indicated alcohol involvement in 530 (72.0%). The criminal code conviction rate for impaired driving was 4.7 percent for drivers with 0.08 percent ≤ BAC < 0.16 percent and 13.6 percent for drivers with BAC > 0.16 percent. The following factors were associated with higher odds of police indicating alcohol involvement: (1) increasing blood alcohol levels, (2) a prior record of impaired driving, (3) involvement in a single-vehicle crash, (4) involvement in a nighttime crash, and (5) traffic violations or unsafe driving actions recorded by police.
Police recognized and documented alcohol involvement in 72 percent of injured drivers with BAC ≥ 0.05 percent. Police documentation of alcohol involvement was more common at higher BAC levels, in nighttime or single-vehicle crashes, for drivers who committed traffic violations or drove unsafely, and for drivers with a prior record of impaired driving. The low conviction rate of injured impaired drivers does not appear to be due to police inability to recognize alcohol involvement.
[Show abstract][Hide abstract] ABSTRACT: While a substantial literature exists demonstrating a strong association of alcohol and intentional injury, less is known about the association of intentional injury with recreational drug use, either alone, or in combination with alcohol.
The risk of intentional injury due to alcohol and other drug use prior to injury is analyzed in a sample of emergency department (ED) patients.
Logistic regression was used to examine the predictive value of alcohol and drug use on intentional versus non-intentional injury in a probability sample of ED patients in Vancouver, BC (n = 436).
Those reporting only alcohol use were close to four times more likely (OR = 3.73) to report an intentional injury, and those reporting alcohol combined with other drug(s) almost 18 times more likely (OR = 17.75) than those reporting no substance use. Those reporting both alcohol and drug use reported drinking significantly more alcohol (15.7 drinks) than those reporting alcohol use alone (5 drinks).
These data suggest that alcohol in combination with other drugs may be more strongly associated with intentional injury than alcohol alone.
The strong association of alcohol combined with other drug use on injury may be due to the increased amount of alcohol consumed by those using both substances, and is an area requiring more research with larger samples of intentional injury patients. (Am J Addict 2013;22:87-92).
American Journal on Addictions 03/2013; 22(2):87-92. DOI:10.1111/j.1521-0391.2013.00316.x · 1.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
This study examined the impact of transportation infrastructure at intersection and non-intersection locations on bicycling injury risk.
In Vancouver and Toronto, we studied adult cyclists who were injured and treated at a hospital emergency department. A case–crossover design compared the infrastructure of injury and control sites within each injured bicyclist's route. Intersection injury sites (N=210) were compared to randomly selected intersection control sites (N=272). Non-intersection injury sites (N=478) were compared to randomly selected non-intersection control sites (N=801).
At intersections, the types of routes meeting and the intersection design influenced safety. Intersections of two local streets (no demarcated traffic lanes) had approximately one-fifth the risk (adjusted OR 0.19, 95% CI 0.05 to 0.66) of intersections of two major streets (more than two traffic lanes). Motor vehicle speeds less than 30 km/h also reduced risk (adjusted OR 0.52, 95% CI 0.29 to 0.92). Traffic circles (small roundabouts) on local streets increased the risk of these otherwise safe intersections (adjusted OR 7.98, 95% CI 1.79 to 35.6). At non-intersection locations, very low risks were found for cycle tracks (bike lanes physically separated from motor vehicle traffic; adjusted OR 0.05, 95% CI 0.01 to 0.59) and local streets with diverters that reduce motor vehicle traffic (adjusted OR 0.04, 95% CI 0.003 to 0.60). Downhill grades increased risks at both intersections and non-intersections.
These results provide guidance for transportation planners and engineers: at local street intersections, traditional stops are safer than traffic circles, and at non-intersections, cycle tracks alongside major streets and traffic diversion from local streets are safer than no bicycle infrastructure.
[Show abstract][Hide abstract] ABSTRACT: Adverse drug events (ADEs) are unintended and harmful consequences of medication use. They are associated with high health resource use and cost. Yet, high levels of inaccuracy exist in their identification in clinical practice, with over one-third remaining unidentified in the emergency department (ED). The study objective was to derive clinical decision rules (CDRs) that are sensitive for the detection of ADEs, allowing their systematic identification early in a patient's hospital course.
This was a prospective observational cohort study carried out in two Canadian tertiary care hospitals. Participants were adults presenting to the ED having ingested at least one prescription or over-the-counter medication within 2 weeks. Nurses and physicians evaluated patients for standardized clinical findings. A second evaluator performed interobserver assessments of predictor variables in a subset of patients. Pharmacists, who were blinded to the predictor variables, evaluated all patients for ADEs. An independent committee reviewed and adjudicated cases where the ADE assessment was uncertain or the pharmacist's diagnosis differed from the physician's working diagnosis. The primary outcome was an ADE that required a change in medical therapy, diagnostic testing, consultation, or hospital admission. CDRs were derived using kappa coefficients, chi-square statistics, and recursive partitioning.
Among 1,591 patients, 131 (8.2%, 95% confidence interval [CI] = 7.0% to 9.7%) were diagnosed with the primary outcome. The following variables were associated with ADEs and were used to derive two CDRs: 1) presence of comorbid conditions, 2) antibiotic use within 7 days, 3) medication changes within 28 days, 4) age ≥ 80 years, 5) arrival by ambulance, 6) triage acuity, 7) recent hospital admission, 8) renal failure, and 9) use of three or more prescription medications. The more sensitive rule had a sensitivity of 96.7% (95% CI = 91.8% to 98.6%) and required 40.8% (95% CI = 37.7% to 42.9%) of patients to have medication review. The more specific rule had a sensitivity 90.8% (95% CI = 81.4% to 95.7%) and required 28.3% of patients to proceed to medication review.
The authors derived CDRs that identified patients with ADEs with high sensitivity. These rules may improve the identification of ADEs early in a patient's hospital course while limiting the number of patients requiring a detailed medication review.
Academic Emergency Medicine 06/2012; 19(6):640-9. DOI:10.1111/j.1553-2712.2012.01379.x · 2.01 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To examine the role of the protein S100B as a biomarker for traumatic brain injury (TBI) in the presence of acute alcohol intoxication.
A total of 159 patients who presented to a large urban level 1 trauma center in Vancouver, British Columbia, Canada, were included. Patients were classified into 4 clinical groups-medical controls (MC), trauma controls (TC), uncomplicated mild TBI (MTBI), and definite TBI (DTBI)-and 2 day-of-injury alcohol intoxication groups (ie, sober and intoxicated).
Blood samples were collected within 8 hours of injury.
Protein S100B concentration (μg/L; Sangtec 100 Elisa, DiaSorin, Stillwater, Minnesota).
Higher S100B levels were found in patients who sustained a TBI than in those in the MC and TC groups (DTBI & MTBI >TC & MC). There was a positive linear relation between S100B levels and brain injury severity (DTBI > MTBI). Alcohol consumption at the time of injury did not generally affect S100B levels. The S100B levels had medium diagnostic accuracy for the majority of patients, with the exception of the DTBI-sober group in which S100B levels had very high diagnostic accuracy.
Patients with uncomplicated MTBIs and DTBIs had much higher levels of S100B than MC and TC participants. This biomarker had medium diagnostic accuracy for detecting DTBI in the presence of alcohol intoxication and very high accuracy in sober patients.
The Journal of head trauma rehabilitation 01/2012; 27(2):123-34. DOI:10.1097/HTR.0b013e31820e6840 · 2.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A substantial literature exists demonstrating the risk of injury from alcohol, but less is known about the association of alcohol in combination with other drugs and injury. This study examined the risk of injury associated with alcohol and drug use prior to the event.
Case-crossover analysis was used to estimate the relative risk (RR) of injury due to alcohol use alone, compared with alcohol in combination with other drug use in a sample of emergency department injured patients from two sites in Vancouver, British Columbia (n = 443). Alcohol and drug use in the 6 h prior to injury was compared with the patient's use of these substances during the same 6 h period the day prior and the week prior to injury.
Using multiple matching for the two control time periods, RR of injury was significantly related to both alcohol use (RR = 3.3) and to alcohol combined with drug use (RR = 3.0), but not to drug use alone. Effect modification was found only for age for alcohol combined with drug use, with a significant increase in injury risk (P = 0.087) for those over 30.
While a similar elevated risk of injury was found for alcohol use alone and alcohol used with other drugs, the literature suggests that alcohol in combination with some drugs may be potentially more risky for injury occurrence. Findings suggest the need for future research on risk of injury for specific alcohol and drug combinations.
Drug and Alcohol Review 08/2011; 31(4):431-8. DOI:10.1111/j.1465-3362.2011.00341.x · 1.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Patient safety events (PSEs) are common in healthcare and may be particularly prevalent in complex care settings such as emergency departments (EDs). Systems for reporting, analyzing, learning from and responding to incidents are promoted as a means to reduce adverse events by facilitating feedback, learning and system change. However, only 4-50% of PSEs are reported. Under-reporting masks the true number of PSEs and may reduce our ability to learn from and prevent repeat events. The goal of this study was to identify barriers that prevent PSE reporting and incentives that encourage reporting. Semi-structured interviews were carried out with front-line nursing staff and nurse managers in EDs across British Columbia to explore their perception of barriers to and incentives for PSE reporting. Interviews were recorded, transcribed, checked for accuracy and entered into NVivo 8 software. Data were analyzed thematically as they were acquired, and emerging themes were explored in subsequent interviews. One hundred six interviews were conducted with staff from 94 of the 98 EDs in British Columbia. Six main barriers to PSE reporting were identified: (1) time constraints, (2) a sense of futility, (3) fear of reprisal, (4) a lack of education on PSE reporting, (5) reports being viewed as indicators of incompetence and (6) an inaccessibility of reporting forms. Incentives for reporting included valuing PSE reporting, the availability of alternative reporting pathways and feedback and visible changes resulting from PSE reports. We identified barriers that restrain nurses from reporting PSEs and incentives that facilitate reporting. Our findings should be considered when developing systems to report and learn from PSEs.
[Show abstract][Hide abstract] ABSTRACT: To examine the relation between diffusion tensor imaging (DTI) of the corpus callosum and postconcussion symptom reporting following mild traumatic brain injury (MTBI).
Sixty patients with MTBI and 34 patients with orthopedic/soft-tissue injuries (Trauma Controls) prospectively enrolled from consecutive admissions to a level 1 trauma center.
Diffusion tensor imaging of the corpus callosum was undertaken using a Phillips 3T scanner at 6 to 8 weeks postinjury. Participants also completed a postconcussion symptom checklist. The MTBI group was divided into 2 subgroups based on the International Classification of Diseases, Tenth Revision symptom criteria for postconcussion disorder (PCD): PCD Present (n = 21), PCD Absent (n = 39).
Measures of fractional anisotropy and mean diffusivity for the genu, body, and splenium of the corpus callosum. Participants also completed the British Columbia Post-Concussion Symptom Inventory.
The MTBI group reported more postconcussion symptoms than the trauma controls. There were no significant differences between MTBI and trauma control groups on all DTI measures. In the MTBI sample, there were no significant differences on all DTI measures between those who did and did not meet the International Classification of Diseases, Tenth Revision research criteria for postconcussion disorder.
These data do not support an association between white matter integrity in the corpus callosum and self-reported postconcussion syndrome 6 to 8 weeks post-MTBI.
The Journal of head trauma rehabilitation 06/2011; 27(3):188-98. DOI:10.1097/HTR.0b013e318217f0ad · 2.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Our objectives are to describe the outcomes of patients presenting to the emergency department (ED) because of an adverse drug event and to compare them with outcomes of patients presenting for other reasons.
This prospective observational study was conducted at Vancouver General Hospital, a 955-bed tertiary care hospital. We prospectively enrolled adults presenting to the ED between March and June 2006, using a systematic sampling algorithm. Pharmacists and physicians independently evaluated patients for adverse drug events. An independent committee reviewed and adjudicated cases in which assessments were discordant or uncertain. Data from the index visit were linked to vital statistics, administrative health services utilization, and cost of care data.
Of 1,000 patients, 122 (12.2%; 95% confidence interval [CI] 10.3% to 14.4%) presented to the ED because of an adverse drug event. Of these, 48 presented because of an adverse drug reaction (one type of adverse drug event defined as an unintended response that occurred despite use of an appropriate drug dosage). We found no difference in mortality among patients presenting with and without adverse drug reactions (14.6% versus 5.9%; hazard ratio 1.57; 95% CI 0.70 to 3.52). After adjustment, patients with adverse drug events had a higher risk of spending additional days in the hospital per month (6.3% versus 3.4%; odds ratio 1.52; 95% CI 1.43 to 1.62) and higher rate of outpatient health care encounters (1.73 versus 1.22; rate ratio 1.20; 95% CI 1.03 to 1.40). The adjusted median monthly cost of care was 1.90 times higher (Can $325 versus $96; 95% CI 1.18 to 3.08).
ED patients presenting with an adverse drug event incurred greater health services utilization and costs during a 6-month follow-up period compared with patients presenting for other reasons.
Annals of emergency medicine 02/2011; 58(3):270-279.e4. DOI:10.1016/j.annemergmed.2011.01.003 · 4.68 Impact Factor