The economic burden of carpal tunnel syndrome: long-term earnings of CTS claimants in Washington State

BACKGROUND: The long-term earnings losses borne by injured workers, beyond those covered by workers' compensation insurance, are rarely estimated. The post-claim earnings of a cohort of carpal tunnel syndrome (CTS) claimants are tracked over a period of 6 years and compared to the earnings of claimants with either upper extremity fractures or dermatitis. METHODS: Quarterly earnings records of 4,443 workers in Washington State who filed claims with the State Fund in 1993 or 1994 for CTS are compared to those of 2,544 with upper-extremity fracture claims and 1,773 with medical-only dermatitis claims. Multivariate regression was used to identify the effect of injury type on earnings from that of other potential predictors. RESULTS: CTS claimants recover to about half of their pre-injury earnings level relative to that of comparison groups after 6 years; they also endured periods on time-loss three times longer than claimants with upper extremity fractures. CTS surgery claimants had better outcomes than those who did not have surgery. Earnings recovery fractions among CTS claimants were better for workers who: (1) were younger; (2) had stable pre-claim employment; (3) lived in the Puget sound area; (4) worked for large businesses; (5) worked in non-construction/transportation industries; or (6) were in the higher pre-injury earnings categories. Cumulative excess loss of earnings of the 4,443 CTS claimants was 197 million dollars to 382 million dollars over 6 years, a loss of 45,000-89,000 dollars per claimant. This underscores the importance of prevention, early diagnosis, and accommodation for return to work.     

The association between neck pain intensity, physical functioning, depressive symptomatology and time-to-claim-closure after whiplash

Time-to-claim-closure is a common outcome in cohort studies of whiplash injuries. However, its relationship to health recovery is unknown. We investigated the association between neck pain, physical functioning, depressive symptomatology and time-to-claim-closure in a Saskatchewan cohort of 5398 whiplash claimants in 1994-1995. Participants were surveyed five times over 1 year. In 1995, the insurance system changed from tort to no-fault, eliminating compensation for pain and suffering. Under tort, a 10-point increase in pain reduced the claim-closure rate by 13-24% while a 10-point increase in physical functioning increased it by 17%. Depressive symptomatology reduced the claim-closure rate by 37%. Under no-fault, a 10-point increase in pain reduced the claim-closure rate by 18% while a 10-point increase in physical functioning increased it by 10-35%. The presence of depressive symptomatology reduced the claim-closure rate by 36%. The results suggests lower pain, better function and the absence of depressive symptoms are strongly associated with faster time-to-claim-closure and recovery after whiplash, independent of the insurance system.     

Association between body mass index and recovery from whiplash injuries: a cohort study

It is hypothesized that excess weight is a risk factor for delayed recovery from neck pain, such as from whiplash injuries. However, the association between obesity and recovery from whiplash injury has not been studied. The authors examined the association between body mass index and time to recovery from whiplash injuries in a population-based cohort study of traffic injuries in Saskatchewan, Canada. The cohort included 4,395 individuals who made an insurance claim to Saskatchewan Government Insurance and were treated for whiplash injury between July 1, 1994, and December 31, 1995. Of those, 87.7% had recovered by November 1, 1997. No association was found between baseline body mass index and time to recovery. Compared with individuals with normal weight, those who were underweight (hazard rate ratio = 0.88, 95% confidence interval: 0.73, 1.06), overweight (hazard rate ratio = 1.01, 95% confidence interval: 0.94, 1.09), and obese (hazard rate ratio = 0.99, 95% confidence interval: 0.90, 1.08) had similar rates of recovery, even after adjustment for other factors. The results do not support the hypothesis that individuals who are overweight or obese have a worse prognosis for whiplash.     

Injury, Compensation Claims and Prognosis: Part I*

Little attention is usually devoted to the effects of litigationand compensation claims on the clinical course and prognosisof injured people. The paper is part of an enquiry into therelationship of injury, compensation and subsequent prognosisas judged from the medical reports of 584 patients, the majorityof whom had had a recent single injury.The epidemiology hasbeen studied comparing the age, sex and occupation of compensation-claimingpatients to the general population and a group of casualty attenders.Compensation claimants are seen to be different judged by allthese standards. A large number of patients had trivial injuries and these showedan unexpected delay in return to work, sometimes more than ayear. The most trivial injuries seem to do very little betterthan intermediate injuries as far as return to work is concerned,and the factors that influence this are discussed under theheadings of age, occupation, the presence or absence of backinjuries, the type of treatment offered, compensation neurosisand general motivation. ⁰Requests for reprints should be addressed to: Mr J. E. Woodyard, Orthopaedic Surgeon, Staffordshire General Infirmary, Stafford, ST16 2PA.     

Psychosocial Factors Related to Return to Work Following Rehabilitation of Whiplash Injuries

INTRODUCTION: The present study examined the effects of pain chronicity on the responsiveness of psychosocial variables to intervention for whiplash injuries. METHODS: Participants (N = 75) were work disabled patients with a diagnosis of Whiplash Grade II and were clients in a 10-week community-based, psychosocial intervention aimed at facilitating return to work. Individuals were classified as subacute (4-12 weeks; N = 25), early chronic (3-6 months; N = 25), and chronic (6-18 months; N = 25). Patients in the three groups were matched on sex (13 men, 12 women) and age (+/-2 years). Patients completed measures of pain severity, self-reported disability, pain catastrophizing and fear of movement at pre-treatment, mid-treatment and post-treatment. RESULTS: Return to work rates were 80, 72 and 32% for the subacute, early chronic and chronic groups, respectively. Individuals in the chronic group, compared to individuals in the subacute or early chronic groups, had significantly more elevated pre-treatment scores on measures of pain catastrophizing, F(2, 74) = 9.6, P < .001, and fear of movement, F(2, 74) = 3.4, P < .05. The magnitude of treatment-related reductions in catastrophizing, fear of movement and pain intensity was comparable across groups. However, individuals who were absent from work for more than 6 months showed the least amount of change in self-reported disability through the course of treatment. CONCLUSIONS: The findings suggest that self-reported disability is particularly resistant to change as the period of work disability extends over time. The findings emphasize the importance of early intervention and the need to develop strategies that specifically target disability beliefs in patients with whiplash injuries.     

Road traffic accidents before and after seatbelt legislation--study in a district general hospital.

Injuries among samples of car accident cases attending the Accident & Emergency (A & E) department of a District General Hospital (DGH) in the year before and after the introduction of seat belt legislation were classified applying the Abbreviated Injury Scale using information recorded in the patient case notes. Those who died or did not attend an A & E department were not included in the sampling frame. The number of those who escaped injury increased by 40% and those with mild and moderate injuries decreased by 35% after seatbelt legislation. There was a significant reduction in soft tissue injuries to the head. Only whiplash injuries to the neck showed a significant increase.     

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

ObjectiveThis 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 SettingData 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.ResultsWhen 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.ConclusionTo 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.     

Development and evaluation of a categorization methodology for occupational back and shoulder injuries using claims data

Administrative claims datasets have great potential for health services researchers who wish to evaluate patient care on a large scale across providers, but categorizing patients’ primary health conditions from these data can be challenging. The goal of this work is to describe and evaluate a methodology to assign workers compensation claimants to meaningful groups within back and shoulder injuries using claims data. Claims data from a large multi-state workers compensation insurance dataset were used to assign eligible claimants to condition and subcondition groups using available ICD9 codes. Assignments were evaluated against body part indicators, severity indicators, resource utilization, and specific clinical interventions. Of the 575,967 claimants who met inclusion criteria, 54,066 claimants were designated as shoulder injuries and 118,772 were designated as back injuries. Within back and shoulder injuries, claimants were assigned to more specific groups known as subconditions. For both back and shoulder injuries, there were statistically significant differences between subconditions in several categories of resource utilization (p < 0.01 for all). For each of nine specific clinical interventions, the hypothesized corresponding subcondition had statistically significantly higher utilization than other subconditions (p < 0.01). This methodology could be an important tool to health services researchers who wish to target interventions or examine trends in cost and service utilization among meaningful groups of claimants.     

Capturing cases in workers' compensation databases: the example of neck pain

BACKGROUND: There is a need to more accurately enumerate workers with musculoskeletal injuries who make lost-time claims to workers compensation boards. The objective of this study is to develop an approach to more accurately enumerate these workers. METHODS: Lost-time claims to the Ontario Workplace Safety & Insurance Board (WSIB) were reviewed. Using neck pain as an example, nature of injury and part of body codes were identified to classify cases. Claims of a random sample of 434 claimants were reviewed. The proportion of claimants classified as having neck pain was computed. RESULTS: The proportion of claimants classified with soft-tissue injuries to the neck varied from 0.88 for codes including "neck/cervical region," 0.69 for "back region" to 0.05 for those coded as "shoulder/upper arm." CONCLUSIONS: Restricting the enumeration of injuries to specific part of body codes can lead to a gross underestimation of the magnitude of soft-tissue disorders in epidemiological studies using workers' compensation data. The proposed approach leads to more accurate enumeration.     

Comparing severity of impairment for different permanent upper extremity musculoskeletal injuries

The labor market impact of upper extremity musculoskeletal injuries that result in permanent disability was estimated using data from the State of California. Administrative data on disability evaluations and resulting ratings was matched to data on the earnings of over 7000 injured workers. Using these data, labor market experience pre- and postinjury was tracked. Each injured worker was matched to a set of control workers who worked at the same firm, had the same tenure at the firm, and earned the same income at the time of injury. By comparing the injured and uninjured workers, lost earnings and the impact of injury on return to work was estimated. Evidence of considerable lost earnings resulting from injury was found. The results are compared to disability ratings that are used to set compensation under California's workers' compensation program. The disability rating was also found to predict poorly differences across upper extremity injuries in losses. In particular, those with shoulder injuries have larger losses than those with elbow or wrist injuries, despite receiving the same disability ratings.     

Support groups for injured workers: process and outcomes

We evaluated the efficacy of a support group for injured workers as a low-cost intervention that might modify chronicity and improve outcome among workers' compensation claimants with chronic musculoskeletal disorders. This study examined the impact of support groups on injured workers with musculoskeletal injuries in relation to four health indicators: pain, somatization, depression, and pain-locus-of-control. We held nine support groups between October 1992 and March 1994. A total of 62 subjects completed the groups. The evaluation of the support group program employed a type of quasi-experimental design, a nonequivalent control group design. A comparison group was created for purposes of evaluation from Workers' Compensation Board of Alberta claimants who did not participate in the groups. We found that participation in the support groups did not seem to affect the well-being of injured workers by reducing their levels of pain, somatization, and depression, and/or by altering their pain-locus-of-control. The results do not necessarily rule out any beneficial effects of participating in support groups. However, these methods applied to this type of support group showed no demonstrable effect.     

Poverty status of worker compensation claimants with permanent impairments

Poverty levels have proven to be pernicious in Canada, with particular groups at heightened risk of poverty. Given that people with disabilities are consistently identified as among those ‘at risk’, we seek to determine the extent to which injured workers/worker compensation claimants who had sustained bodily impairments live in poverty. Employing two poverty indicators, we describe the poverty levels of Ontario injured workers with permanent impairments at an average of 52 months post-injury. For one indicator, we describe proximity to/depth of poverty; and in bivariate and multivariate analyses, we examine the factors associated with poverty in the post-injury period. Estimated poverty rates for the injured worker sample – ranging from 17 to 26% – compare unfavourably to published estimates of poverty in the general population of working-aged Canadians/Ontarians and equate to those of Canadians/Ontarians with disabilities. Pre-injury employment characteristics and income status only partly account for post-injury poverty, pre-injury health does not. Sample members in post-injury poverty were more likely to report having sustained multiple injuries at the workplace, were less likely to have returned to employment or to have recovered pre-injury earnings, and yet contributed significantly more to post-injury household incomes than those not in post-injury poverty. We discuss the implications of the findings for worker compensation boards that adjudicate and have final authority on worker claims for compensation for harms sustained in the workplace.     

Job Performance Failure and Occupational Carpal Tunnel Claims

Using a sample of one job type from one firm (to hold job tasks and sick leave/disability policy constant), we estimate the effect of demographic variables, job performance warnings, and workers' compensation benefits on the propensity to file a carpal tunnel syndrome (CTS) loss work-time claim. We find that disciplinary notices increase the employees' propensity to file a CTS claim. State maximum workers' compensation benefits are also positively related to CTS claim frequency, however, the relationship is not statistically significant. CTS claimants respond differently than other sprain/strain claimants to benefits and to gender. In particularly, women have relatively more CTS claims, while men have relatively more other sprain/strain claims in our sample. The estimates here underscore the importance of psychosocial factors in the filing of occupational CTS and sprain injuries claims.     

Predicting treatment failure in the subacute injury phase using the Orebro Musculoskeletal Pain Questionnaire: an observational prospective study in a workers' compensation system

OBJECTIVE: The goal of the present study was to examine if patient scores on a brief biopsychosocial screening questionnaire--the Orebro Musculoskeletal Pain Questionnaire (OMPQ)--could predict clinical discharge status ("fit" vs "not fit" for return to work) after a standardized 6-week physical therapy-based work conditioning program. METHODS: The OMPQ was administered to a derivation sample of 200 injured workers with soft tissue injuries before beginning treatment. A clinical cutoff score of 147 was subsequently tested in a second validation sample of 211 injured workers. RESULTS: The OMPQ was able to correctly predict the discharge status of 85% of claimants. CONCLUSIONS: These results suggest that the OMPQ can facilitate clinical decision-making through early identification of individuals likely to fail a unidisciplinary physical therapy program and who may benefit from more complete biopsychosocial treatment.     

Economic consequences of workplace injuries and illnesses: lost earnings and benefit adequacy.

BACKGROUND: This is the first study based on individual data to estimate earnings lost from virtually all reported workplace injuries and illnesses in a state. METHODS: We estimated lost earnings from workplace injuries and illnesses occurring in Wisconsin in 1989-90, using workers' compensation data and 6 years of unemployment insurance wage data. We used regression techniques to estimate losses relative to a comparison group. RESULTS: The average present value of losses projected 10 years past the observed period is over $8,000 per injury. Women lose a greater proportion of their preinjury earnings than do men. Replacement of after-tax projected losses averages 64% for men and 50% for women. CONCLUSIONS: Overall, workers with compensated injuries and illnesses experienced discounted pre-tax losses projected to total over $530,000,000 (1994 dollars), with about 60% of after-tax losses replaced by workers' compensation. Generally, groups losing over eight weeks' work received workers' compensation benefits covering less than 40% of their losses.     

Trends in Sickness Certification of Injured Workers by General Practitioners in Victoria,Australia

Background General practitioners (GPs) play a critical role in facilitating injured workers return to work via their ability to certify capacity to return to employment. However, little is known about the sickness certification patterns of GPs in the context of workers’ compensation claims. Aim To determine if GPs’ sickness certification behaviour has changed between 2003 and 2010 in Victoria, Australia. Method Retrospective population-based cohort study of all injured workers with an accepted compensation claim. Sickness certification rates per 1,000 working population per annum were calculated. General regression models adjusted for workers’ age and annual claim number were fitted to summarize changes in count and duration (expressed as incidence rate ratios or IRRs) of unfit for work (UFW) versus alternate duties (ALT) certificates within six categories of work-related injury and disease. Results 92,134 UFW and 28,293 ALT certificates were identified. A significant decrease in the unadjusted annual certification rates per 1,000 working population was observed. However, after adjusting for the annual number of claims and age, the IRRs of certificates increased over time. The rate of injuries and IRRs of certificates varied across affliction categories, IRRs being higher in mental health conditions in women than in men (IRR: 0.40, 95 % CI 0.38–0.41 vs. IRR: 0.17, 95 % CI 0.16–0.18). The duration of certificates remained stable, with the ALT being longer than UFW certificates in all claimants. Conclusion Our findings indicate that GPs in Victoria issue an increasing number of UFW sickness certificates each year. Further research is required to investigate the reasons for such practises.     

Reliability and Safety of Functional Capacity Evaluation in Patients with Whiplash Associated Disorders

Introduction Whiplash-associated disorders (WAD) are a burden for both individuals and society. It is recommended to evaluate patients with WAD at risk of chronification to enhance rehabilitation and promote an early return to work. In patients with low back pain (LBP), functional capacity evaluation (FCE) contributes to clinical decisions regarding fitness-for-work. FCE should have demonstrated sufficient clinimetric properties. Reliability and safety of FCE for patients with WAD is unknown. Methods Thirty-two participants (11 females and 21 males; mean age 39.6 years) with WAD (Grade I or II) were included. The FCE consisted of 12 tests, including material handling, hand grip strength, repetitive arm movements, static arm activities, walking speed, and a 3 min step test. Overall the FCE duration was 60 min. The test–retest interval was 7 days. Interclass correlations (model 1) (ICCs) and limits of agreement (LoA) were calculated. Safety was assessed by a Pain Response Questionnaire, observation criteria and heart rate monitoring. Results ICCs ranged between 0.57 (3 min step test) and 0.96 (short two-handed carry). LoA relative to mean performance ranged between 15 % (50 m walking test) and 57 % (lifting waist to overhead). Pain reactions after WAD FCE decreased within days. Observations and heart rate measurements fell within the safety criteria. Conclusions The reliability of the WAD FCE was moderate in two tests, good in five tests and excellent in five tests. Safety-criteria were fulfilled. Interpretation at the patient level should be performed with care because LoA were substantial.     

Physical workplace factors and return to work after compensated low back injury: a disability phase-specific analysis

Little is known about predictors of duration of work disability (DOD). This cohort study of 433 workers' compensation claimants estimated DOD for job, injury, and demographic factors during consecutive disability phases using Cox regression analysis. DOD was calculated from administrative records. Results show that DOD increases with the time spent bending and lifting or pushing or pulling heavy objects at work, but it is unrelated to sitting, standing, or vibration. Younger age, longer pre-injury employment, less severe injuries, and a previous back injury predicted shorter disability, the latter factor only during the subacute/chronic disability phases. The effect of injury severity decayed over time. This study demonstrates the usefulness of a phase-specific analysis and shows that physical job and injury factors have a significant and time-varying impact on DOD.     

Preliminary report of mortality among workers compensated for work-related asthma

BACKGROUND: Although fatalities due to asthma have been reported among subjects with occupational asthma (OA) associated with re-exposure, groups of subjects with work-related asthma have not been systematically followed up for mortality. During a review of compensation claims for asthma in Ontario, we identified 3 respiratory deaths among subjects previously compensated for OA for whom their surviving spouses received death benefits. This suspected "cluster" prompted us to undertake an investigation to examine mortality pattern among workers compensated for work-related asthma. METHODS: Subjects receiving compensation for OA or aggravation of asthma (AA) between 1980 and 1993, and a comparison sample of workers with claims for musculoskeletal injuries during the same period were identified from the Ontario Workers' Compensation Board. We also identified another comparison group of non-compensated asthmatic patients seen at a hospital clinic during the same period. The files of those with work-related asthma were reviewed to determine if OA or AA was adequately documented. Mortality was ascertained by linkage with the Mortality Database at the Ontario Cancer Registry through 1996. We compared the mortality of the three groups with that expected in the general population of Ontario using SMRs, and directly by proportional-hazards regression. RESULTS: The study included 3,070 subjects: 1,112 with work-related OA/AA with adequate documentation, 1,556 with work-related injuries, and 402 patients with non-work-related asthma. Of the 66 deaths identified, only 2 deaths were due to asthma, both in the work-related asthma group: one from the index cluster and one not previously identified. A second index death was coded as dying from COPD not elsewhere classified (ICD9 496), while the third index death also died of asthma but there was not sufficient information documenting OA to include the subject in the analyses. As compared with the general population, there were fewer deaths than expected from most causes, except for deaths among the work-related asthma claimants and the nonwork-related asthma patients from respiratory diseases (SMRs 1.3 and 5.9, respectively; 0.5 among injury claimants), all chronic obstructive lung disease (ICD9 490-496; SMRs 2.3 and 7.7, respectively), and asthma (SMRs 18.2 and 0, respectively). In direct comparison of the work-related asthma claimants with the injury claimants, the risk of death appeared elevated from respiratory disease (RR 2.6) and ischemic heart disease (IHD) (RR 2.8) but the confidence intervals included unity. CONCLUSIONS: This preliminary report raises the possibility that serious outcomes, including excess deaths from respiratory disease, in particular asthma, may occur among those with work-related asthma even in the absence of re-exposure. However, the findings are inconclusive given that the number of deaths was small and we identified only one new asthma death in addition to the index cluster. We also observed for the first time that deaths due to circulatory disease, particularly IHD, may also be increased among such workers; this needs to be confirmed elsewhere.     

Veterans seeking disability benefits for post-traumatic stress disorder: who applies and the self-reported meaning of disability compensation

Assumptions about the characteristics and motivations of individuals pursuing disability status are well known. However, policy, programming and interventions need to be based on information about the actual sociodemographic characteristics of disabled individuals, as well as their goals in seeking disability status. In this study, we focus on veterans seeking disability compensation for post-traumatic stress disorder (PTSD) from the United States Department of Veterans Affairs. We present information on their life circumstances and their self-reported reasons for valuing the obtainment of veterans' disability status on the basis of PTSD. There was considerable variability in the background of veterans seeking disability status on the basis of PTSD. Of concern, only about half of these individuals were receiving any mental health treatment at the time of application. Most claimants reported seeking disability compensation for symbolic reasons, especially for acknowledgement, validation and relief from self-blame. Reasons having to do with improved finances were less frequently endorsed, although the importance of obtaining improved solvency through disability status decreased as income increased. The sense of investment in obtaining a sense of self-acceptance and acceptance from others through disability status varied by sociodemographic variables. Overall, findings suggest that individuals seeking disability benefits may have unmet mental health care needs, and that policy makers, investigators and providers should consider material benefit as one of many possible reasons for engaging in a disability compensation system.