Are people who claim compensation "cured by a verdict"? A longitudinal study of health outcomes after whiplash.

This study examines whether the lure of injury compensation prompts whiplash claimants to overstate their symptoms. Claim settlement is the intervention of interest, as it represents the point at which there is no further incentive to exaggerate symptoms, and neck pain at 24 months is the outcome of interest. Longitudinal data on neck pain scores and timing of claim settlement were regressed, controlling for the effect of time on recovery, to compare outcomes in claimants who had and had not settled their compensation claims. The results show clearly that removing the financial incentive to over-report symptoms has no effect on self-reported neck pain in a fault-based compensation scheme, and this finding concurs with other studies on this topic. Policy decisions to limit compensation in the belief that claimants systematically misrepresent their health status are not supported empirically Claimants do not appear to be "cured by a verdict".

Does injury compensation lead to worse health after whiplash? A systematic review.

One might expect that injury compensation would leave injured parties better off than they would otherwise have been, yet many believe that compensation does more harm than good. This study systematically reviews the evidence on this "compensation hypothesis" in relation to compensable whiplash injuries. PubMed, CINAHL, EMBASE, PEDro, PsycInfo, CCTR, Lexis, and EconLit were searched from the date of their inception to April 2010 to locate longitudinal studies, published in English, comparing the health outcomes of adults exposed/not exposed to compensation-related factors. Studies concerning serious neck injuries, using claimants only, or using proxy measures of health outcomes were excluded. Eleven studies were included. These examined the effect of lawyer involvement, litigation, claim submission, or previous claims on pain and other health outcomes. Among the 16 results reported were 9 statistically significant negative associations between compensation-related factors and health outcomes. Irrespective of the compensation-related factor involved and the health outcome measured, the quality of these studies was similar to studies that did not find a significant negative association: most took some measures to address selection bias, confounding, and measurement bias, and none resolved the potential for reverse causality bias that arises in the relationship between compensation-related factors and health. Unless ambiguous causal pathways are addressed, one cannot draw conclusions from statistical associations, regardless of their statistical significance and the extent of measures to address other sources of bias. Consequently, there is no clear evidence to support the idea that compensation and its related processes lead to worse health.

Research on injury compensation and health outcomes: ignoring the problem of reverse causality led to a biased conclusion.

OBJECTIVE: This study highlights the serious consequences of ignoring reverse causality bias in studies on compensation-related factors and health outcomes and demonstrates a technique for resolving this problem of observational data. STUDY DESIGN AND SETTING: Data from an English longitudinal study on factors, including claims for compensation, associated with recovery from neck pain (whiplash) after rear-end collisions are used to demonstrate the potential for reverse causality bias. Although it is commonly believed that claiming compensation leads to worse recovery, it is also possible that poor recovery may lead to compensation claims--a point that is seldom considered and never addressed empirically. This pedagogical study compares the association between compensation claiming and recovery when reverse causality bias is ignored and when it is addressed, controlling for the same observable factors. RESULTS: When reverse causality is ignored, claimants appear to have a worse recovery than nonclaimants; however, when reverse causality bias is addressed, claiming compensation appears to have a beneficial effect on recovery, ceteris paribus. CONCLUSION: To avert biased policy and judicial decisions that might inadvertently disadvantage people with compensable injuries, there is an urgent need for researchers to address reverse causality bias in studies on compensation-related factors and health.

Is compensation "bad for health"? A systematic meta-review.

OBJECTIVE: There is a common perception that injury compensation has a negative impact on health status, and systematic reviews supporting this thesis have been used to influence policy and practice decisions. This study evaluates the quality of the empirical evidence of a negative correlation between injury compensation and health outcomes, based on systematic reviews involving both verifiable and non-verifiable injuries. DESIGN: Systematic meta-review (a "review of reviews"). DATA SOURCES: PubMED, CINAHL, EMBASE, PEDro, PsycInfo, EconLit, Lexis, ABI/INFORM, The Cochrane Library, and the AHRQ EPC were searched from the date of their inception to August 2008, and hand searches were conducted. REVIEW METHODS: Selection criteria were established a priori. Included systematic reviews examined the impact of compensation on health, involved adults, were published in English and used a range of outcome measures. Two investigators independently applied standard instruments to evaluate the methodological quality of the included reviews. Data on compensation scheme design (i.e., the intervention) and outcome measures were also extracted. RESULTS: Eleven systematic reviews involving verifiable and non-verifiable injuries met the inclusion criteria. Nine reviews reported an association between compensation and poor health outcomes. All of them were affected by the generally low quality of the primary (observational) research in this field, the heterogeneous nature of compensation laws (schemes) and legal processes for seeking compensation, and the difficulties in measuring compensation in relation to health. CONCLUSION: Notwithstanding the limitations of the research in this field, one higher quality review examining a single compensation process and relying on primary studies using health outcome (rather than proxy) measures found strong evidence of no association between litigation and poor health following whiplash, challenging the general belief that legal processes have a negative impact on health status. Moves to alter scheme design and limit access to compensation on the basis that it is "bad for health" are therefore premature, as evidence of such an association is unclear.

Whiplash and the compensation hypothesis.

STUDY DESIGN: Review article. OBJECTIVE: To explain why the evidence that compensation-related factors lead to worse health outcomes is not compelling, either in general, or in the specific case of whiplash. SUMMARY OF BACKGROUND DATA: There is a common view that compensation-related factors lead to worse health outcomes ("the compensation hypothesis"), despite the presence of important, and unresolved sources of bias. The empirical evidence on this question has ramifications for the design of compensation schemes. METHODS: Using studies on whiplash, this article outlines the methodological problems that impede attempts to confirm or refute the compensation hypothesis. RESULTS: Compensation studies are prone to measurement bias, reverse causation bias, and selection bias. Errors in measurement are largely due to the latent nature of whiplash injuries and health itself, a lack of clarity over the unit of measurement (specific factors, or "compensation"), and a lack of appreciation for the heterogeneous qualities of compensation-related factors and schemes. There has been a failure to acknowledge and empirically address reverse causation bias, or the likelihood that poor health influences the decision to pursue compensation: it is unclear if compensation is a cause or a consequence of poor health, or both. Finally, unresolved selection bias (and hence, confounding) is evident in longitudinal studies and natural experiments. In both cases, between-group differences have not been addressed convincingly. CONCLUSION: The nature of the relationship between compensation-related factors and health is unclear. Current approaches to testing the compensation hypothesis are prone to several important sources of bias, which compromise the validity of their results. Methods that explicitly test the hypothesis and establish whether or not a causal relationship exists between compensation factors and prolonged whiplash symptoms are needed in future studies.

Complexities in understanding the role of compensation-related factors on recovery from whiplash-associated disorders: discussion paper 2.

STUDY DESIGN: Focused discussion. OBJECTIVE: To present some of the complexities in conducting research on the role of compensation and compensation-related factors in recovery from whiplash-associated disorders (WAD) and to suggest directions for future research. SUMMARY OF BACKGROUND DATA: There is divergence of opinion, primary research findings, and systematic reviews on the role of compensation and/or compensation-related factors in WAD recovery. METHODS: The topic of research of compensation/compensation-related factors was discussed at an international summit meeting of 21 researchers from diverse fields of scientific enquiry. This article summarizes the main points raised in that discussion. RESULTS: Traffic injury compensation is a complex sociopolitical construct, which varies widely across jurisdictions. This leads to conceptual and methodological challenges in conducting and interpreting research in this area. It is important that researchers and their audiences be clear about what aspect of the compensation system is being addressed, what compensation-related variables are being studied, and what social/economic environment the compensation system exists in. In addition, summit participants also recommended that nontraditional, sophisticated study designs and analysis strategies be employed to clarify the complex causal pathways and mechanisms of effects. CONCLUSION: Care must be taken by both researchers and their audiences not to overgeneralize or confuse different aspects of WAD compensation. In considering the role of compensation/compensation-related factors on WAD and WAD recovery, it is important to retain a broad-based conceptualization of the range of biological, psychological, social, and economic factors that combine and interact to define and determine how people recover from WAD.