Knut Stavem

Akershus universitetssykehus, Kristiania (historical), Oslo County, Norway

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Publications (113)259.67 Total impact

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    ABSTRACT: To withhold and withdraw treatment are important and difficult decisions made in the intensive care unit (ICU). The aim of this study was to investigate the incidence of withholding or withdrawing treatment, characteristics of the patients, and how these decision processes were handled and documented in a general ICU from 2007 to 2009 in a university hospital in Norway. Patient characteristics and outcomes of treatment were prospectively registered. We retrospectively reviewed the medical records for information on limitations in treatment. In total, 1287 patients were admitted to the ICU. The ICU mortality was 208 (16%), and the hospital mortality was 341 (26%). In total, 301 patients (23%) had treatment withheld or withdrawn. Medical and unscheduled surgical patients with limitations in treatment had higher Simplified Acute Physiology Score II (P < 0.001) and were older (P < 0.001) than those without limitations in treatment. The most common main reason for withdrawing treatment was poor prognosis. According to the medical records, the patient was involved in the decision-making regarding withdrawal of treatment in only 2% of the cases, and the patient's relatives were involved in the decision-making in 77% of the cases. In 12% of the cases, type of treatment withdrawn was not documented. Withholding or withdrawing treatment in the ICU was common. Medical and unscheduled surgical patients with limitations in treatment were older and more severely ill than patients without limitations. There is a potential for better documentation of the processes regarding withholding or withdrawing life-sustaining intensive care treatment.
    Acta Anaesthesiologica Scandinavica 01/2014; · 2.36 Impact Factor
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    ABSTRACT: Early identification of patients with a prolonged stay due to acute exacerbation of chronic obstructive pulmonary disease (COPD) may reduce risk of adverse event and treatment costs. This study aimed to identify predictors of prolonged stay after acute exacerbation of COPD based on variables on admission; the study also looked to establish a prediction model for length of stay (LOS). We extracted demographic and clinical data from the medical records of 599 patients discharged after an acute exacerbation of COPD between March 2006 and December 2008 at Oslo University Hospital, Aker. We used logistic regression analyses to assess predictors of a length of stay above the 75th percentile and assessed the area under the receiving operating characteristic curve to evaluate the model's performance. We included 590 patients (54% women) aged 73.2±10.8 years (mean ± standard deviation) in the analyses. Median LOS was 6.0 days (interquartile range [IQR] 3.5-11.0). In multivariate analysis, admission between Thursday and Saturday (odds ratio [OR] 2.24 [95% CI 1.60-3.51], P<0.001), heart failure (OR 2.26, 95% CI 1.34-3.80), diabetes (OR 1.90, 95% CI 1.07-3.37), stroke (OR 1.83, 95% CI 1.04-3.21), high arterial PCO2 (OR 1.26 [95% CI 1.13-1.41], P<0.001), and low serum albumin level (OR 0.92 [95% CI 0.87-0.97], P=0.001) were associated with a LOS >11 days. The statistical model had an area under the receiver operating characteristic curve of 0.73. Admission between Thursday and Saturday, heart failure, diabetes, stroke, high arterial PCO2, and low serum albumin level were associated with a prolonged LOS. These findings may help physicians to identify patients that will need a prolonged LOS in the early stages of admission. However, the predictive model exhibited suboptimal performance and hence is not ready for clinical use.
    International Journal of COPD 01/2014; 9:99-105.
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    ABSTRACT: Bakground: The objectives of this study were; (1) to assess the prevalence and frequency of headache in patients referred to polysomnography (PSG) due to a clinical suspicion of obstructive sleep apnea (OSA) or another sleep disturbance and compare with a reference population, and (2) to assess the association of OSA severity with headache and headache frequency. A total of 784 participants filled in a headache questionnaire between 2003 and 2009 at the Department of Clinical Neurophysiology, Akershus University Hospital. Of these patients 477 were suspected to have OSA, and 307 had other sleep complaints. We assessed the prevalence of headache and monthly headache frequencies, as well as sleep apnea severity using an apnea-hypopnea index (AHI). The association of headache and monthly headache frequencies with PSG subgroups was assessed using multivariate logistic and ordered logistic regression analysis. The frequency of headache was not associated with the severity of OSA. Patients referred to a sleep study for any reason had higher odds ratio (OR) for having experienced headache during the past year than population controls after adjustment for age, gender and education, i.e. patients with normal AHI had OR of 3.56, patients with OSA had OR of 3.51, and patients with other sleep disturbances had OR of 3.33. Similarly, the adjusted OR of being in a higher category of monthly headache frequency compared to controls was higher in those with normal AHI (OR 3.42), OSA (OR 3.29), and other sleep disturbances (OR 3.00). The odds of headache and headache frequency were higher in subjects referred to a PSG for any sleep disturbance independently of OSA, compared to general population controls. However, there was no association between experiencing headache during the past year or headache frequency with OSA severity.
    The Journal of Headache and Pain 11/2013; 14(1):90. · 2.78 Impact Factor
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    ABSTRACT: For clinical trial design and for clinical practice, it is of importance to assess factors associated with placebo response in patients with refractory epilepsy. We determined factors associated with placebo response in 359 adult patients with refractory focal epilepsy participating in three randomized placebo-controlled trials of the new antiepileptic drug lacosamide. At the end of the randomized 12-week maintenance period, 81 (23%) of the 359 patients randomized to placebo achieved at least a 50% seizure reduction (responders) compared to baseline. In contrast, 278 (77%) patients did not achieve a 50% seizure reduction (non-responders) compared to baseline. In multivariate analysis, five factors, which were present prior to the exposure to placebo, were found to be associated with placebo response. Higher age at study entry improved the chances of placebo response for each year [p=0.023, odds ratio (OR) 1.034 (95% confidence interval (95% CI): 1.005-1.063)]. In contrast, a lower chance of placebo response was seen with age at diagnosis of epilepsy of 6-20years compared to ≤5years [p=0.041, OR 0.475 (95% CI: 0.232-0.971)]. A history of 7 or more prior lifetime AEDs lowered the chance of achieving placebo response compared to 1-3 prior lifetime AEDs [p<0.001, OR 0.224 (95% CI: 0.101-0.493)] as did a baseline seizure frequency >10 seizures per 28days compared to ≤5 seizures per 28days [p=0.026, OR 0.431 (95% CI: 0.205-0.904)]. Prior epilepsy surgery lowered the likelihood of placebo response [p=0.02, OR 0.22 (95% CI: 0.062-0.785)]. We suggest that age at exposure to placebo, age at diagnosis of epilepsy, the number of prior lifetime AEDs, baseline seizure frequency and a history of epilepsy surgery appear to be associated with placebo response in adults with refractory focal epilepsy.
    Epilepsy & Behavior 03/2013; · 2.06 Impact Factor
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    ABSTRACT: INTRODUCTION: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a common cause of hospitalization, and the readmission rate is high. We aimed to determine whether patients discharged from a pulmonary department (PD) after an AECOPD episode had a lower COPD-related readmission rate during the next 12 months than comparable patients discharged from other internal medicine departments (ODs). METHODS: The medical records of 566 patients discharged after an episode of AECOPD between March 2006 and December 2008 at Oslo University Hospital, Aker were reviewed retrospectively. Demographic and medical data, together with number of readmissions due to AECOPD during 12 months following the index admission were extracted. We matched patients discharged from the PD and the ODs using a propensity score and used the paired t-test to compare COPD-related readmission rates between the matched patients. RESULTS: In total 481 patients were included in the analysis, 247 patients discharged from the PD and 234 from ODs. The propensity score matching process resulted in 155 well-matched pairs. The mean (standard deviation) number of readmissions within one year was 0.8 (1.3) for the PD versus 1.1 (1.9) for ODs (p=0.09). After adjusting for exposure time, the corresponding readmission rates were 1.1 (2.3) and 1.6 (4.0) per year, respectively (p=0.17). CONCLUSION: There was little difference in COPD-related readmission rates between comparable patients discharged from the PD and the ODs after an AECOPD during one year following the index admission.
    The Clinical Respiratory Journal 01/2013; · 1.66 Impact Factor
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    ABSTRACT: Background: National EQ-5D value sets are developed because preferences for health may vary in different populations. UK values are lower than US values for most of the 243 possible EQ-5D health states. Although similar protocols were used for data collection, analytic choices regarding how to model values from the collected data may also influence national value sets. Participants in the UK and US studies assessed the same subset of 42 EQ-5D health states using the time trade-off (TTO) method. However, different methods were used to transform negative values to a range bounded by 0 and -1, and values for all 243 health states were estimated using two different regression models. The transformation of negative values is inconsistent with expected utility theory, and the choice of which transformation method to use lacks a theoretical foundation. Objectives: Our objectives were to assess how much of the observed difference between the UK and US EQ-5D value sets may be explained by the choice of transformation method for negative values relative to the choice of regression model and the differences between elicited TTO values in the respective national studies (datasets). Methods: We applied both transformation methods and both regression models to each of the two datasets, resulting in eight comparable value sets. We arranged these value sets in pairs in which one source of difference (transformation method, regression model or dataset) was varied. For each of these paired value sets, we calculated the mean difference between the two matching values for each of the 243 health states. Finally, we calculated the mean utility gain for all possible transitions between pairs of EQ-5D health states within each value set and used the difference in transition scores as a measure of impact from changing transformation method, regression model or dataset. Results: The mean absolute difference in values was 1.5 times larger when changing the transformation method than when using different datasets. The choice of transformation method had a 3.2 times larger effect on the mean health gain (transition score) than the choice of dataset. The mean health gain in the UK value set was 0.09 higher than in the US value set. Using the UK transformation method on the US dataset reduced this absolute difference to 0.02. The choice of regression model had little overall impact on the differences between the value sets. Conclusions: Most of the observed differences between the UK and US value sets were caused by the use of different transformation methods for negative values, rather than differences between the two study populations as reflected in the datasets. Changing the regression model had little impact on the differences between the value sets.
    PharmacoEconomics 11/2012; · 2.86 Impact Factor
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    ABSTRACT: Purpose: A frequently used valuation method for health state valuation is the time trade- off (TTO) method. Typically, valuation studies control for individual characteristics focusing on demographic variables like age, sex, education, and geography. We hypothesized that valuation of hypothetical health states are more prone to variance along other individual variables, including personality, beliefs, attitudes, and personal experience. The purpose of the study was to compare the impact of typical demographic variables to the impact of candidate variables from these other domains. Method: 511 respondents participated in a web survey. The participants were fairly representative for the Norwegian population with respect to age and sex. Each participant valued eight health states of varying severity as described with the EQ-5D system. Additionally we asked questions about factors we hypothesized could affect their general willingness to trade away time: Agreement with euthanasia, number of children, the personality trait neuroticism, and the extent to which they considered themselves to be religious, to which extent they believed in a life after death. In a multivariate regression we used the TTO value as dependent variable and demographic variables and the other factors with potential influence as independent variables. Result: Linear regression of TTO scores on individual variables Coeff Beta p Intercept 0.299 <.001 sex (1 = female) -0.02 -0.019 0.322 age (years) -0.001 -0.021 0.314 9-12 years of education -0.046 -0.04 0.28 >12 years of education -0.024 -0.022 0.554 Marital status (single vs. attached) -0.014 -0.012 0.561 Children under 18 (dummy) 0.048 0.043 0.036 Belief in life after death (dummy) 0.01 0.02 0.326 Religiousity (5 point scale of agreement) 0.001 0.001 0.947 Attitudes toward euthanasia (mean of three 5 point scales) -0.074 -0.141 <.001 Neuroticism (normalized Z scores) -0.028 -0.049 0.012 Conclusion: Typical demographic variables did not significantly influence TTO values. However, having children in the home, attitudes toward euthanasia, and the personality trait neuroticism appear to significantly influence valuation of hypothetical health states. These variables were selected from their respective domains as likely candidates, and suggest that valuation of health states may be informed more by attitudes, personality, and experiences than the usual demographic variables. Variable relevance should be carefully considered.
    The 34th Annual Meeting of the Society for Medical Decision Making; 10/2012
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    ABSTRACT: Purpose: In population health surveys, national representativeness is of the utmost importance. Due to increased availability of online computers and increased computer literacy, the current gold standard of using postal surveys is challenged. The objective of this study was to compare the population representativeness of web-based and postal survey modes in a health survey setting where national representativeness is vital. Method: We developed postal and web variants of a health valuation survey with intended to maximize representativeness in the adult Norwegian population. The postal version was mailed to a random sample of 5000 persons over the age of 18 drawn from the Norwegian Population Registry. For the web-survey, we invited 1936 respondents from the market research company Synovate’s standing panel of willing survey participants. We compared the two surveys in terms of distribution of respondents’ demographic characteristics and EQ-5D self-ratings. Result: 4899 (postal) and 1936 (web) respondents were reached, of whom 1276 (26%) and 1003 (50,2%), respectively, submitted complete forms. Characteristics are listed in the table: Table: Demographics and EQ-5D self-ratings, percentages Demographics Postal Web Norway EQ-5D Postal Web Age, years Across dimensions 18-29 13,40 10,17 20,02 No problems 49,4 43,0 30-39 14,34 13,96 17,78 Any problems 50,6 57,0 40-49 17,63 20,04 18,71 Any extreme 5,0 7,6 50-59 19,20 22,33 16,29 60-69 17,08 26,12 13,65 Some problems 70-79 11,29 6,48 7,74 Mobility 15,2 15,4 80+ 7,05 0,90 5,81 Self-care 3,0 2,3 Usual activities 15,9 19,0 Edu, years Pain/discomfort 39,9 44,3 <=9 13,40 10,17 29,80 Anxiety/depression 19,9 20,9 9-12 31,97 34,00 42,90 13-15 19,20 22,33 20,80 Extreme problems 16+ 17,08 26,12 6,50 Mobility 0,0 0,1 Self-care 0,2 0,0 Sex Usual activities 1,1 1,4 Male 48,20 48,16 49,57 Pain/discomfort 3,6 6,0 Female 51,80 51,84 50,43 Anxiety/depression 1,1 1,3 Conclusion: The web survey outperformed the postal in terms of demographic representativeness, particularly for education, albeit with low participation rates over the age of 70. The distributions of reported EQ-5D problems were similar, but web respondents reported more problems, possibly due to lower mean education levels. Severe health problems are likely to be underrepresented. Web surveys may already be superior to postal surveys in terms of representativeness, and may be recommended for use in studies in countries with widespread access to computers and high levels of computer literacy.
    The 34th Annual Meeting of the Society for Medical Decision Making; 10/2012
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    ABSTRACT: Background: Several countries have now passed laws that place limitations on where smokers may smoke. A range of smoking-cessation treatments have become available, many of which have documented increased quit rates. Population surveys show that most smokers wish to quit, and most non-smokers would prefer to reduce the prevalence of smoking in society. The strengths of these preferences, however, as measured by their willingness to pay (WTP), have not yet been investigated. Objective: This study aims to identify variables that explain variations in people's answers to WTP questions on smoking-cessation treatments. Methods: A representative sample of the Norwegian population was asked their WTP in terms of an earmarked contribution to a public smoking-cessation programme. A sub-group of daily smokers was, in addition, asked about their WTP for a hypothetical treatment that would remove their urge to smoke. The impact of variation in the question format (different opening bids) on stated WTP was compared with that of factors suggested by economic theory, such as quit-rate effectiveness, degree of addiction as measured by the 12-item Cigarette Dependence Scale (CDS-12), and degree of peer group influence as measured by the proportion of one's friends who smoke. Results: In both programmes, the most important determinant for explaining variations in WTP was the size of the opening bid. Differences in quit-rate effectiveness did not matter for people's WTP for the smoking-cessation programme. Addiction, and having a small proportion of friends who smoke, were positively associated with smokers' WTP to quit smoking. Conclusion: Variations in WTP were influenced more by how the question was framed in terms of differences in opening bids, than by variables reflecting the quality (effectiveness) and need (addiction level) for the good in question. While the WTP method is theoretically attractive, the findings that outcomes in terms of different quit rates did not affect WTP, and that WTP answers can be manipulated by the chosen opening bid, should raise further doubts on the ability of this method to provide valid and reliable answers that reflect true preferences for health and healthcare.
    Applied Health Economics and Health Policy 09/2012;
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    ABSTRACT: PURPOSE: Health state values are by convention anchored to 'perfect health' and 'death.' Attitudes toward death may consequently influence the valuations. We used attitudes toward euthanasia (ATE) as a sub-construct for attitudes toward death. We compared the influence on values elicited with time trade-off (TTO), lead-time TTO (LT-TTO) and visual analogue scale (VAS).Since the 'death' anchor is most explicit in TTO, we hypothesized that TTO values would be most influenced by ATE. METHODS: Respondents valued eight EQ-5D health states with VAS, then TTO (n = 328) or LT-TTO (n = 484). We measured ATE on a scale from -2 (fully disagree) to 2 (fully agree) and used multiple linear regressions to predict VAS, TTO, and LT-TTO values by ATE, sex, age, and education. RESULTS: A one-point increase on the ATE scale predicted a mean TTO value change of -.113 and LT-TTO change of -.072. Demographic variables, but not ATE, predicted VAS values. CONCLUSIONS: TTO appears to measure ATE in addition to preferences for health states. Different ways of incorporating death in the valuation may impact substantially on the resulting values. 'Death' is a metaphysically unknown concept, and implications of attitudes toward death should be investigated further to evaluate the appropriateness of using 'death' as an anchor.
    Quality of Life Research 06/2012; · 2.86 Impact Factor
  • American Thoracic Society 2012 International Conference, May 18-23, 2012 • San Francisco, California; 05/2012
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    ABSTRACT: In EuroQol five-dimensional questionnaire valuation studies, each participant typically assesses more than 10 hypothetical health states by using the time trade-off (TTO) method. We wanted to explore potential learning effects when using the TTO method, that is, whether the valuations were affected by the number of previously rated health states (the sequence number). We included 3773 respondents from the US EQ-5D valuation study, each of whom valued 12 health states (plus unconscious) in random order. With linear regression, we used sequence number to predict mean and standard deviations across all health states. We repeated the analysis separately for TTO responses indicating a state better than death and a state worse than death. Each TTO value requires a specific number of choice iterations. To test whether respondents used fewer iterations with experience, we used linear regression with sequence number as the independent variable and number of iterations as the dependent variable. Mean TTO values were fairly stable across the sequence number, but analyzing state better than death and state worse than death values separately revealed a tendency toward more extreme values: state better than death values increased by 0.02, while state worse than death values decreased by 0.21 (P < 0.0001) over the full sequence. The standard deviations increased slightly, while the number of choice iterations was the same over the sequence number. The findings were stable across the levels of health state severity, age, and sex. TTO values become more extreme with increasing experience. Because of the randomized valuation order, these effects do not bias specific health states; however, they reduce the overall validity and reliability of TTO values.
    Value in Health 03/2012; 15(2):340-5. · 2.19 Impact Factor
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    ABSTRACT: Given serious concerns over the adverse effects of enzyme induction, modern nonenzyme-inducing antiepileptic drugs (AEDs) may be preferable, provided they have similar efficacy as enzyme-inducing AEDs. This is currently unclear. Therefore, we performed a meta-analysis of the evidence to determine the placebo-corrected efficacy of adjunctive treatment with modern nonenzyme-inducing AEDs versus modern enzyme-inducing AEDs that are on the market for refractory focal epilepsy. Of 322 potentially eligible articles reviewed in full text, 129 (40%) fulfilled eligibility criteria. After excluding 92 publications, 37 studies dealing with a total of 9,860 patients with refractory focal epilepsy form the basis for the evidence. The overall weighted pooled-risk ratio (RR) in favor of enzyme-inducing AEDs over placebo was 2.37 (95% confidence interval [CI] 1.77-3.18, p < 0.001) for at least 50% seizure reduction and 4.45 (2.26-8.76, p < 0.001) for seizure freedom. The corresponding weighted pooled RR in favor of nonenzyme-inducing AEDs over placebo was 2.28 (95% CI 2.03-2.57, p < 0.001) for at least 50% seizure reduction and 3.23 (95% CI 2.23-4.67, p < 0.001) for seizure freedom. In a meta-regression analysis in the same sample with at least 50% seizure reduction as outcome, the ratio of RRs for enzyme-inducing AEDs (eight studies) versus nonenzyme-inducing AEDs (29 studies) was 1.01 (95% CI 0.77-1.34, p = 0.92)). Similarly, the ratio of RRs for a seizure-free outcome for enzyme-inducing AEDs (six studies) versus nonenzyme-inducing AEDs (19 studies) was 1.38 (95% CI 0.60-3.16, p = 0.43). Although the presence of moderate heterogeneity may reduce the validity of the results and limit generalizations from the findings, we conclude that the efficacy of adjunctive treatment with modern nonenzyme-inducing AEDs is similar to that of enzyme-inducing AEDs. Given the negative consequences of enzyme induction, our data suggest that nonenzyme-inducing AEDs may be useful alternatives to enzyme-inducing AEDs for treatment of refractory focal epilepsy.
    Epilepsia 03/2012; 53(3):512-20. · 3.96 Impact Factor
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    ABSTRACT: EQ-5D valuation studies are usually performed using the time tradeoff (TTO) method, which is costly and time consuming. We focused on 2 properties that particularly characterize TTO: the initial choice task categorizing health states as better than death (BTD), worse than death (WTD), or equal to death (ETD), and unwillingness to trade (UTT) lifetime to improve health. The aim of this study was to estimate the value of the information to be gained from continuing the conventional TTO tasks beyond the initial question and the extent to which mean-based EQ-5D tariff values could be predicted through a simplified method of categorizing health states into BTD, WTD, ETD, and UTT. We used data from the UK EQ-5D valuation study (n = 2997). We designed an abbreviated system with only 4 values (collapsed TTO [cTTO]) based on the 4 response categories and assigned values as follows: WTD = -.5, ETD = 0, BTD = .5, and UTT = 1. Based on the mean cTTO scores for the valued health states, we created a regression-based cTTO tariff, which was compared with the conventional (full) TTO tariff (fTTO) by regressing 1) the fTTO means on cTTO means and 2) the fTTO tariff on the cTTO tariff. WTD values were unrelated to health state severity. Correlation between the means of fTTO and means of cTTO was >.999, and tariff values from fTTO correlated with tariff values from cTTO at r > .999. Once respondents have classified health states as UTT, BTD, ETD, or WTD, the TTO procedure adds little further information to the tariff values. The WTD task fails to discriminate between good and bad health states. TTO valuation could likely be simplified using cTTO.
    Medical Decision Making 01/2012; 32(4):569-77. · 2.89 Impact Factor
  • K Stavem, O M Rønning
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    ABSTRACT: Few studies have assessed the influence of the organization of stroke care on long-term survival. To compare survival over 12 years after stroke between subjects treated in an acute stroke unit (SU) and those treated in general medical wards (GMW). In total, 550 subjects ≥60 years of age with acute stroke were prospectively allocated according to date of birth (day of the month) to treatment in a SU with relatively short length of stay or GMWs. We assessed survival through a link to the register of Statistics Norway. Groups were compared using Kaplan-Meier analysis on an intention-to-treat basis. Of the 550 eligible subjects, 271 were allocated to a SU and 279 to GMWs. There still was no difference in mortality over 12 years between the groups (P = 0.15, log-rank test) An acute SU offering early treatment and rehabilitation did not offer better long-term mortality after stroke in patients ≥60 years old than initial treatment in GMWs.
    Acta Neurologica Scandinavica 12/2011; 124(6):429-33. · 2.47 Impact Factor
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    ABSTRACT: Purpose: The time trade-off (TTO) method is frequently used to elicit health state values in national valuation studies for the EQ-5D. TTO is used to identify the point of preferential equilibrium between a fixed number of years in an impaired EQ-5D health state and a shorter life in perfect health. Values are anchored at perfect health (1) and death (0). To allow health states considered worse than death (<0), the initial TTO question asks whether the target health state is better, worse, or equal to death. It is conceivable that respondents who are opposed to euthanasia display an aversion to describing health states as worse than death, resulting in elevated TTO scores. The aim of this study was to investigate whether respondent attitudes towards euthanasia affect health state values elicited using the regular TTO method, and the Lead-Time TTO (LT-TTO), where comparison to death is less direct. Method: Each of 811 members of a survey panel representative of the Norwegian general population valued eight EQ-5D health states on a visual-analogue scale (VAS) and with the TTO method (n=328) or with the alternative LT-TTO (n=483). We assessed attitudes towards euthanasia (ATE) using three items (passive euthanasia, active euthanasia, and assisted suicide), resulting in values ranging from -2 (strongly against euthanasia) to 2 (strongly in favour). After exclusions due to inconsistencies and incomplete responses, 400 LT-TTO and 213 regular TTO respondents were included in analyses. We used multiple linear regressions to predict VAS, TTO and LT-TTO values by ATE, sex, age and education. Results: For VAS values, the only statistically significant predictor was sex. For regular and Lead-Time TTO, the only significant predictor was ATE; a one point increase on the ATE scale was associated with a mean TTO value of -.109 (p<.001) and .075 (p<.001) for regular and LT-TTO, respectively. Conclusions: In this study TTO values were associated with attitudes towards euthanasia, while VAS values were not. The effect was greater for regular TTO than LT-TTO, possibly because death is less salient in the LT-TTO than the regular method. The findings indicate that the TTO method measures attitude towards death rather than, or in addition to, preferences for the health states in question.
    The 33rd Annual Meeting of the Society for Medical Decision Making; 10/2011
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    ABSTRACT: Purpose: Neuroticism, a personality trait associated with negative affect, is strongly related to perception of health, self-assessed health, and numerous measures of mental and physical health. The EQ-5D descriptive system is a generic form intended as an objective measure of health status. It has five dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression), each with three levels (no, some, or extreme problems), describing 243 different combination health states. The objective of this study was to assess the association between neuroticism, as expressed by a trait measure, and self-descriptions of health state using the EQ-5D. Method: We collected descriptions of own health on the EQ-5D and the 12-item neuroticism scale of the NEO Five Factor Inventory (NEO FFI) from a representative sample of 2279 persons from the adult Norwegian population. We calculated Pearson’s r between neuroticism (Z-scores based on Norwegian norms) and scores in the five EQ-5D dimensions. We then used multiple linear regression to predict US and Danish EQ-5D tariff values corresponding to the respondents’ EQ-5D profiles, using age, sex, and neuroticism scores as predictors. Result: Neuroticism was significantly correlated with all five EQ-5D dimensions (mobility .174, self-care .151, usual activities .206, pain/discomfort .216, anxiety/depression .409 (p<.001 for all). When predicting US and Danish EQ-5D tariff values, age (+1 year = -.002 in both), female sex (-.042 and -.050, respectively) and neuroticism score (+1 SD = -.058 and -.071, respectively) were significant predictors (p<.001 for all). Conclusion: Neuroticism was a strong predictor of EQ-5D tariff values. The association between neuroticism score and EQ-5D dimension scores was strongest for anxiety/depression. Our findings indicate that the personality trait (or, at least, the measure of it) is substantially influenced by health status, that self-ratings on the EQ-5D are influenced by neuroticism, or both. Our cross-sectional study is unsuited to determine the causal relationship between neuroticism and self-ratings of health. The bi-directional relationship should be investigated further using a longitudinal design, since it could prove important for the interpretation and validity of both individual level and patient-group level EQ-5D data.
    The 33rd Annual Meeting of the Society for Medical Decision Making; 10/2011
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    ABSTRACT: Purpose: A recurrent challenge in health-related quality of life (HRQoL) research is how to handle comorbidity, as mean EQ-5D tariff-values (mtv) are usually only known for single health states. Several methods have been proposed to derive joint-state values (jsv) from single-state values (ssv), but comparison of the predicted jsvs with the elicited jsvs from groups of patients who actually have the target comorbidities reveals limited success. The aim of this research is investigating a new jsv predictor (jsp). Method: We analysed data from the Medical Expenditure Survey Panel (MEPS, N≈3·104), revealing a Pearson’s R of .9995368 when correlating the number of comorbid disorders (Clinical Classification-Codes) with the mtvs for respondents with the same number of comorbid disorders. We proceeded to construct a novel jsp P based on the idea that the mtv u for a single state population is best viewed as a measure of that single state’s number m of units of morbidity (um) by a conversion f(u)=m obtained by an initial regression as suggested by the strong correlation above. The predictor aggregates the converted mtvs u and v of two single-states, before predicting the corresponding jsv’s value: P(u,v,z) = f –1(f(u)+f(v)-z) Above, z is a parameter intended to account for some overlap between conditions, which for the current research have been set to 1. The resulting predictor is on the form u+v-c where c is a constant depending on f. Though reminiscent of the additive predictor, conceptually it differs in treating the ssv’s as proxies for ums rather than as utilities: additivity arise from the linear relation empirically observed and not on any a priori assumption. Result: The jsp outperformed various traditional predictors (additive, multiplicative, minimum and a general predictor proposed in [1] w.r.t. the MEPS data set. We next tested the concept on data (N≈104) elicited from a Norwegian inpatient population. Again P outperformed the other. Conclusion: It is striking that the predictor, conceived by analysing a general population, transfers so readily to the inpatients. Although its construction relies on a linear regression for each data set, it does not rely on distinguishing between morbidities. We recommend adopting P as a canonical candidate predictor, as well as further research into how the parameter z can improve accuracy. [1]_Bo_Hu_and_Alex_Z._Fu:_Predicting_Utility_for_Joint_Health_States:_A_General_Framework_and_a_New_Nonparametric_Estimator,_in_MDM_SEP-OCT_2010
    The 33rd Annual Meeting of the Society for Medical Decision Making; 10/2011
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    ABSTRACT: EQ-5D tariffs are typically based on general population valuations studies, but whether valuations of experienced health (EH) or hypothetical health (HH) are more appropriate is disputed. Previous comparisons of valuations of EH and HH have focused on absolute differences in dimension-specific regression coefficients. We examined differences in the relative importance attributed to the EQ-5D dimensions between EH and HH valuations of EQ-5D states in the United States. We used the regression model from the US EQ-5D valuation study on EH ratings from the 2000-2003 Medical Expenditure Panel Survey and on HH ratings from the US EQ-5D valuation study conducted in 2001. We then compared patterns in the relative magnitudes of coefficients that corresponded to the five dimensions. In the HH model, self-care and pain/discomfort were the most important dimensions, while usual activities were the least important. In the EH model, usual activities were the most important dimension, while self-care was one of the least important. The findings reveal considerable differences between stated preferences for HH and ratings of EH, particularly for self-care and usual activities. The findings accentuate the importance of the debate about which groups' values should be used in medical priority setting.
    Quality of Life Research 09/2011; 21(6):1005-12. · 2.86 Impact Factor
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    ABSTRACT: Reports on quality of life of kidney donors include small populations with variable response rates. The aim was to evaluate quality of life in kidney donors in a large cross-sectional study. Through the Norwegian Renal Registry we contacted all 1984 kidney donors in the period 1963-2007 with a response rate of 76%. All received the Short-Form-36 (SF-36) survey form and a questionnaire specifically designed for kidney donors. SF-36 scores for a subgroup (n = 1414) of kidney donors were not inferior to a general population sample, adjusted for age, gender and education. When asked to reconsider, a majority stated that they still would have consented to donate. Risk factors for having doubts were graft loss in the recipient (OR 3.1, p < 0.001), medical problems after donation (OR 3.7, p < 0.001), unrelated donor (OR 2.2, p = 0.01) and less than 12 years since donation (OR 1.8, p = 0.04). Older age at donation was associated with lower risk (OR 0.98, p = 0.03). Compared with other donors, those expressing doubts had inferior SF-36 scores. Norwegian kidney donors are mostly first-degree relatives. They are fully reimbursed and offered life-long follow-up. All inhabitants are provided universal healthcare. This should be considered when extrapolating these results to other countries.
    American Journal of Transplantation 06/2011; 11(6):1315-9. · 6.19 Impact Factor

Publication Stats

1k Citations
259.67 Total Impact Points

Institutions

  • 2002–2013
    • Akershus universitetssykehus
      Kristiania (historical), Oslo County, Norway
  • 1999–2013
    • University of Oslo
      • • Institute of Clinical Medicine
      • • Department of Behavioural Sciences in Medicine
      • • Division of Medicine
      • • Department of Radiology and Nuclear Medicine (ARN)
      Kristiania (historical), Oslo County, Norway
  • 2009–2012
    • Centre Hospitalier de Luxembourg
      Letzeburg, Luxembourg, Luxembourg
  • 1999–2011
    • Oslo University Hospital
      • Department of Neurosurgery
      Oslo, Oslo, Norway
  • 2004–2010
    • Norwegian Knowledge Centre for the Health Services
      Kristiania (historical), Oslo County, Norway
  • 2005
    • Akershus universitetssykehus HF
      Kristiania (historical), Oslo County, Norway