Work Disability Outcomes Research Articles

Attention-Deficit/Hyperactivity Disorder Medications and Work Disability and Mental Health Outcomes

ImportanceIndividuals with attention-deficit/hyperactivity disorder (ADHD) often have comorbid psychiatric conditions. Relatively little is known about how specific ADHD medications are associated with overall treatment outcomes among these patients.ObjectiveTo investigate the association of the use of specific ADHD medications with hospitalization outcomes and work disability among adolescents and adults with ADHD.Design, Setting, and ParticipantsThis nationwide register-based cohort study identified individuals (aged 16-65 years) with ADHD from Swedish nationwide registers of inpatient health care, specialized outpatient health care, sickness absence, and disability pension during the years 2006 to 2021. Data analysis was performed from November 2022 to August 2023.ExposureUse of specific ADHD medications.Main Outcomes and MeasuresThe main outcome measure was psychiatric hospitalization, and secondary outcomes were suicide attempt and/or death by suicide, nonpsychiatric hospitalization, and work disability (ie, sickness absence or disability pension). The risk of outcomes between use vs nonuse periods of ADHD medications was compared in a within-individual design, where a person acts as their own control, and was analyzed with stratified Cox models.ResultsA total of 221 714 persons with ADHD were included in the study cohort (mean [SD] age, 25.0 [11.2] years; 120 968 male individuals [54.6%]). Methylphenidate was the most commonly used ADHD medication (151 837 individuals [68.5%]), followed by lisdexamphetamine (78 106 individuals [35.2%]) during the follow-up (mean [SD], 7.0 [4.7] years). The following medications were associated with a decreased risk of psychiatric hospitalization: amphetamine (adjusted hazard ratio [aHR], 0.74; 95% CI, 0.61-0.90), lisdexamphetamine (aHR, 0.80; 95% CI, 0.78-0.82), ADHD drug polytherapy (aHR, 0.85; 95% CI, 0.82-0.88), dexamphetamine (aHR, 0.88; 95% CI, 0.83-0.94), and methylphenidate (aHR, 0.93; 95% CI, 0.92-0.95). No associations were found for modafinil, atomoxetine, clonidine, and guanfacine. Decreased risk of suicidal behavior was associated with the use of dexamphetamine (aHR, 0.69; 95% CI, 0.53-0.89), lisdexamphetamine (aHR, 0.76; 95% CI, 0.68-0.84), and methylphenidate (aHR, 0.92; 95% CI, 0.86-0.98). None of the medications was associated with increased risk of nonpsychiatric hospitalization; instead, use of amphetamine, lisdexamphetamine, polytherapy, dexamphetamine, methylphenidate, and atomoxetine were associated with decreased risk of nonpsychiatric hospitalization. The results regarding work disability were significant only for the use of atomoxetine (aHR, 0.89; 95% CI, 0.82-0.97), especially among adolescents and young adults aged 16 to 29 years, (aHR, 0.82; 95% CI, 0.73-0.92).Conclusions and RelevanceIn this nationwide cohort study of adolescents and adults with ADHD, the use of ADHD medication was associated with fewer hospitalizations for both psychiatric and nonpsychiatric morbidity and lower suicidal behavior.

Psychotherapy duration and work disability: A prospective Finnish register study.

The influence of psychotherapy duration on common mental disorder (CMD) outcomes remains a topic of ongoing debate. Whereas most research has focused on CMD symptom change, the evidence on the psychotherapy duration of subsequent CMD-related work disability and the change in psychotropic drug purchases is scarce. We used a register-based cohort representing 33% of the Finnish population. The participants included working-age individuals (N = 12,047, 76% women, mean age = 36) who initiated long-term psychotherapy, between 2014 and 2017. They were followed from 2011 to 2021 and psychotherapy duration ranged from less than a year to over 3 years. We used an interrupted time series design to analyze the psychotherapy duration-dependent changes in CMD-related work disability (primary outcome, operationalized as depression or anxiety-related sickness absence, SA, days) and the annual number of psychotropic drug purchases or distinct drugs purchased (secondary outcomes). There were no differences in the levels of work disability or drug purchases before the psychotherapy. We observed a decreasing level and trend in all outcomes across all psychotherapy duration groups. The largest decline in level was observed in the <1-year duration group (88% decline for SA and 43%-44% for drug purchases) while the smallest decline was in the 3+ years duration group (73% for SA and 27% for drug purchases). Work disability outcomes and duration varied among individuals, even with similar initial mental health-related work disability or use of auxiliary psychotropic treatments. Compared to longer psychotherapy, shorter psychotherapy was associated with sharper improvements.

10.Q. Workshop: Imbalance in use and impact of public psychotherapy – A Finnish working-age population register study

Abstract Mental disorders are globally among the leading causes of disability in the working-age population. Psychotherapies have proven to be effective in the improvement of mental health. The current evidence on the benefits of psychotherapies is mainly based on randomized control trials and patient-reported outcomes, whereas the potential impact of long-term psychological therapy on work disability and income is not so well known. This emphasizes the need for longitudinal studies on the effects of psychological therapies in a ‘real-world study setting’, and on the distribution of the availability and the use of psychological therapies in different populations. In Finland, rehabilitative psychotherapy is the major single form of publicly provided psychological therapy. It is targeted at those aged 16 to 67 who are at risk of disability or not being able to study because of mental health problems. It is granted an annual period (maximum three years), a maximum of 80 sessions per year and 200 sessions per 3 years. From 2011 on this psychotherapy has been statutorily granted to all at risk of work disability due mental health disorders. The number of annual users has increased from 15 757 (2010) to 56 682 (2020). This workshop presents the results from a research project investigating the use and real-world effects of long-term psychotherapy in the Finnish working-age population in the 2010s. It shows 1) whether the use of psychotherapy is associated with subsequent work disability and labour market outcomes (income, employment), 2) how the use of long-term psychotherapy differed between socio-demographic groups in the 2010s in Finland, and 3) the extent to which state-subsidized psychotherapy is linked to the distinctive profiles of mental health problems in the population. The five presentations offer new results from the Rise of Mental Vulnerability in Work Life Study drawn from the national registers. The presentations are mostly based on three randomly selected population cohorts which each included 33% of the 18-64-year-old permanent Finnish residents at the baseline. These data were sampled (sampling years: 2010, 2013, 2016) by and derived from the Population Register maintained by Statistics Finland and included information on various socio-demographic characteristics (e.g., gender, occupation class, region, income). These were linked to the national health registers. Information on reimbursed psychotherapy and mental health indicators (sickness absence, psychotropic drugs, disability benefits) were obtained from the Social Insurance Institution of Finland and complemented by the disability pension data from the Finnish Centre for Pensions. The data provide a unique opportunity to observe how the use of state-subsidized long-term psychotherapy was distributed across population groups in the 2010s, and to the extent to which disability trajectories and economic outcomes have developed in different groups during and after psychotherapeutic treatment. Key messages • Psychotherapy is likely to decrease the risk of work disability and improve labour market outcomes. • The provision of long-term psychotherapy is related to social inequality in the working population.

Out-of-Pocket Spending and Work Loss after Common Surgical Procedures Among Working-Age Adults

INTRODUCTION: Half of surgical patients report financial toxicity, which results from direct out-of-pocket (OOP) cost and indirect loss of income. This study aimed to assess the economic impact of common surgical procedures on patient OOP spending and work loss among working-age adults. METHODS: We used the 2017 to 2019 MarketScan Database to identify adults ages 19 to 64 years who underwent 1 of 20 common surgical procedures. These data were linked to the Health Productivity and Management (HPM) Database, which reports work absence and disability for a subset of employers. Outcomes included spending after index operation, disability, and return to work. Multivariable regression models adjusted for patient demographics and clinical variables. To control for secular trends, we used 4:1 propensity score matching using patient and employment variables. RESULTS: We identified 135,480 patients and 541,920 matched controls. Among this cohort, 25% of patients had a nonelective presentation and 12% had an ICU admission. Spending, missed work, and disability for patients linked to the HPM database are shown in the Table. Nonelective presentation was associated with higher OOP spending and more short-term disability (p < 0.05). Patients requiring ICU stay had higher OOP spending and more missed days of work and disability (p < 0.05). Table. - Six Month Out-of-Pocket Spending and Missed Work after Common Surgical Procedures Variable Surgical patients Matched controls Difference p Value Mean OOP spending (median, IQR) $3,487 ($2,020, $749-3,597) $636 ($12, $0-422) $2,851 <0.001 Any missed work 62.1% 32.5% 29.6% <0.001 Mean total days missed (median, IQR) 23 (15,4-36) 3 (2, 0-4) 20 <0.001 Any short-term disability 36.2% 2.7% 33.5% <0.001 Mean total days of short-term disability (median, SD) 41 (32, 19-56) 35 (15, 0-54) 6 <0.001 Surgical cohorts include common cardiac, vascular, general, and orthopedic procedures. OOP spending represents coinsurance, copays, and deductibles per patient. Missed work and short-term disability outcomes are only for those linked to the HPM database and employed at time of index admission. CONCLUSION: Patients recovering from operation face high OOP payments, miss over a month of work on average, and one in three receive short-term disability benefits. These findings demonstrate the double burden of medical expense and productivity loss and can inform policies for improved financial risk protection after operation.

Differences between men and women in their risk of work injury and disability: A systematic review.

BackgroundHealth responses associated with occupational exposures can vary between men and women.AimsThis study reviewed the work injury and disability risks associated with similar types of occupational exposures for men and women within and across occupations.Materials & MethodsA systematic review was undertaken of observational studies published between 2009 and 2019. Studies were required to empirically compare men and women for associations between occupational exposures and work injury or disability outcomes. Included studies were appraised for methodological quality and medium to high rated studies were compared for risk differences between men and women.ResultsOf 14,006 records identified, 440 articles were assessed for methodological quality, and 33 medium to high rated studies were included and reviewed. Among all occupations, the association between physical exposures, job demands, noise, and repetitive tasks, and injury risk were stronger among men. The relationship between repetitive tasks and sickness absence was stronger among women. Most studies examining psychological exposures found no risk differences for men and women across occupations. Men were at higher injury risk in certain occupations in primary and secondary industry sectors involving physical exposures and some chemical/biological exposures. Women were at higher injury risk for the physical demands and repetitive tasks of health care and aluminum production occupations.ConclusionThis review found that men and women can have different work injury and disability risks, both across and within the same occupations, for some physical exposures and to a lesser extent for some chemical and biological exposures. These differences might be a result of occupation‐specific task differences.

Are Work Demand, Support and Control Associated with Work Ability and Disability during Back Pain Treatment? A Prospective Explorative Study

Background: Low back pain is a multifactorial disease with consequences for work ability and social participation. Improved integration of the work domain in health care management is needed. The aim of this study was to explore the relation between working conditions with outcome of low back pain treatment. Methods: Observational study of 41 patients attending physiotherapy for low back pain. Work demands, support and control were registered at baseline and work ability and disability also at baseline, with follow up after three and nine months. We used mixed-effects models to estimate the longitudinal associations between working conditions and outcome. Results: Higher work demands were related to reduced work ability (−1.1 points, 95% CI: −2.1 to −0.1) and slightly increased disability (5.6 points, 95% CI: 0.5 to 10.7). Lack of social support from colleagues was associated with reduced work ability (−2.7 points, 95% CI: −0.2 to 1.5) and disability (14.0 points, 95% CI: 4.9 to 23.1). Conclusions: This explorative study found associations between work demands and support, and work ability and disability outcome. Screening for psychosocial working conditions may influence the work ability and disability treatment outcome. The results need replication in larger samples and may indicate that patients seeking primary care management for low back pain should be screened for work demands, support and control.

Health and work disability outcomes in parents of patients with schizophrenia associated with antipsychotic exposure by the offspring

This study aimed to identify if antipsychotic exposure in offspring is associated with psychiatric and non-psychiatric healthcare service use and work disability of their parents. This Swedish population-based cohort study was based on data comprising 10,883 individuals with schizophrenia, who had at least one identifiable parent in the nationwide registers, and their parents (N = 18,215). The register-based follow-up during 2006–2013 considered the level of antipsychotic exposure and persistence of use of the offspring, further categorized into first (FG) and second generation (SG) antipsychotics, and orals versus long-acting injections (LAIs). The main outcome measure was parental psychiatric healthcare service use, secondary outcomes were non-psychiatric healthcare use and long-term sickness absence. SG-LAI use was associated with a decreased risk (relative risks [RR] 0.81-0.85) of parental psychiatric healthcare use compared with not using SG-LAI, whereas oral antipsychotics were associated with an increased risk (RRs 1.10–1.29). Both FG- and SG-LAI use by the offspring were associated with a lower risk of long-term sickness absence (range of odds ratios 0.34–0.47) for the parents, compared with non-use of these drugs. The choice of antipsychotic treatment for the offspring may have an impact on work disability and healthcare service use of their parents.

Why does the adverse effect of inappropriate MRI for LBP vary by geographic location? An exploratory analysis

BackgroundEarly magnetic resonance imaging (eMRI) for nonspecific low back pain (LBP) not adherent to clinical guidelines is linked with prolonged work disability. Although the prevalence of eMRI for occupational LBP varies substantially among states, it is unknown whether the risk of prolonged disability associated with eMRI varies according to individual and area-level characteristics. The aim was to explore whether the known risk of increased length of disability (LOD) associated with eMRI scanning not adherent to guidelines for occupational LBP varies according to patient and area-level characteristics, and the potential reasons for any observed variations.MethodsA retrospective cohort of 59,360 LBP cases from 49 states, filed between 2002 and 2008, and examined LOD as the outcome. LBP cases with at least 1 day of work disability were identified by reviewing indemnity service records and medical bills using a comprehensive list of codes from the International Classification of Diseases, Ninth Edition (ICD-9) indicating LBP or nonspecific back pain, excluding medically complicated cases.ResultsWe found significant between-state variations in the negative impact of eMRI on LOD ranging from 3.4 days in Tennessee to 14.8 days in New Hampshire. Higher negative impact of eMRI on LOD was mainly associated with female gender, state workers’ compensation (WC) policy not limiting initial treating provider choice, higher state orthopedic surgeon density, and lower state MRI facility density.ConclusionState WC policies regulating selection of healthcare provider and structural factors affecting quality of medical care modify the impact of eMRI not adherent to guidelines. Targeted healthcare and work disability prevention interventions may improve work disability outcomes in patients with occupational LBP.

Innovations in Occupational Health Care Delivery Can Prevent Entry into Permanent Disability: 8-Year Follow-up of the Washington State Centers for Occupational Health and Education.

Background:Long-term work disability is known to have an adverse effect on the nation’s labor force participation rate. To reduce long-term work disability, the Washington State Department of Labor and Industries established a quality improvement initiative that created 2 pilot Centers of Occupational Health and Education (COHE).Objectives:To document the level of work disability in a sample of injured workers with musculoskeletal injuries and to examine (8-y) work disability outcomes associated with the COHE health care model.Research Design:Prospective nonrandomized intervention study with nonequivalent comparison group using difference-in-difference regression models.Subjects:Intervention group represents 18,790 workers with musculoskeletal injuries treated by COHE providers. Comparison group represents 20,992 workers with similar injuries treated within the COHE catchment area by non-COHE providers.Measures:Long-term disability outcomes include: (1) on disability 5 years after injury; (2) received a state pension for total permanent disability; (3) received total disability income support through the Social Security Disability Insurance program; or (4) a combined measure including any one of the 3 prior measures.Results:COHE patients had a 30% reduction in the risk of experiencing long-term work disability (odds ratio=0.70, P=0.02). The disability rate (disability days per 1000 persons) over the 8-year follow-up for the intervention and comparison groups, respectively, was 49,476 disability days and 75,832 disability days.Conclusions:Preventing long-term work disability is possible by reorganizing the delivery of occupational health care to support effective secondary prevention in the first 3 months following injury. Such interventions may have promising beneficial effects on reversing the nation’s progressively worsening labor force participation rate.

Utilisation of nationwide register data to assess the effectiveness of changes in sickness insurance legislation on work participation and analyse sickness absence and disability retirement trends in Finland

This paper presents examples of various ways of utilising for research purposes large nationwide registers, originally collected for administrative purposes. Merging registers with information on sociodemographic factors can help understand trends in work disability outcomes, such as sickness absence and disability retirement. Quasi-experiments can be designed utilising large register data to look at the effectiveness and cost-effectiveness of interventions on a societal level, such as legislative changes. Examples of such interventions include the introduction and amendment of laws determining the use of part-time sick leave in Finland and the so-called 30-60-90 rule, defining check-points for action for the occupational service provider, the employer and the employee in situations of prolonged sickness absence. Advanced analytical techniques, for example the construction of the propensity score, to increase comparability of studied groups, are especially feasible in large register data. We recommend using nationwide administrative register data for research purposes, where such data are available.

Effect of anti-TNF and conventional synthetic disease-modifying anti-rheumatic drug treatment on work disability and clinical outcome in a multicentre observational cohort study of psoriatic arthritis.

To determine the effect of medical treatment on work disability in patients with active PsA in a real-world setting. Four hundred patients with active PsA commencing or switching to anti-TNF or conventional synthetic DMARD (csDMARD) were recruited to a multicentre UK prospective observational cohort study. Work disability was measured using the work productivity and activity-specific health problem instrument and peripheral joint activity was measured with the disease activity in PsA composite measure. Four hundred patients were recruited, of whom 229 (57.25%) were working (of any age). Sixty-two patients of working age (24%) were unemployed. At 6 months there was a 10% improvement in presenteeism ( P = 0.007) and a 15% improvement in work productivity ( P = 0.001) among working patients commenced on csDMARDs ( n = 164) vs a larger and more rapid 30% improvement in presenteeism ( P < 0.001) and 40% improvement in work productivity ( P < 0.001) among those commenced on anti-TNF therapy ( n = 65). Clinical response was poor among patients commenced on a csDMARD ( n = 272), with an 8.4 point improvement in disease activity in PsA ( P < 0.001) vs those commenced on anti-TNF therapy ( n = 121), who had a 36.8 point improvement ( P < 0.001). We report significant and clinically meaningful improvements in both work disability and clinical outcomes after commencement of anti-TNF therapy in a real-world setting. Improvements in all outcomes among those commencing csDMARDs were slower and of a smaller magnitude.

Extent and Impact of Opioid Prescribing for Acute Occupational Low Back Pain in the Emergency Department

BackgroundInitial management of acute occupational low back pain (AOLBP) commonly occurs in the emergency department (ED), where opioid prescribing can vary from the clinical guidelines that recommend limited use. ObjectiveThe objective of this study was to explore how opioids are prescribed in the ED and the impact on work disability and other outcomes in AOLBP. MethodsA retrospective cohort study was conducted. All acute compensable lost-time LBP cases seen initially in the ED with a date of injury from January 1, 2009 to December 31, 2011 were identified within a nationally representative Workers' Compensation dataset. Multivariate models estimated the effect of early opioids (received within 2 days of ED visit) on disability duration, long-term opioid use, total medical costs, and subsequent surgeries. ResultsOf the cohort (N = 2887), 12% received early opioids; controlling for severity, this was significantly associated with long-term opioid use (adjusted risk ratio = 1.29; 95% confidence interval 1.05–1.58) and increased total medical costs for those in the highest opioid dosage quartile, but not associated with disability duration or subsequent low back surgery. ConclusionsEarly opioid prescribing in the ED for uncomplicated AOLBP increased long-term opioid use and medical costs, and should be discouraged, as opioid use for low back pain has been associated with a variety of adverse outcomes. However, ED providers may be becoming more compliant with current LBP treatment guidelines.

Examining the Relationship Between Productivity Loss Trajectories and Work Disability Outcomes Using the Panel Study of Income Dynamics.

To identify trajectories of productivity loss and examine the relationship between the trajectories and work disability outcomes. Latent class growth analysis of productivity loss was estimated for the ages of 25 to 44 years in the Panel Study of Income Dynamics (N = 4960). Differences among the trajectories for work disability outcomes for the ages of 25 to 64 years were estimated using logistic regression and analysis of variance. A five-group trajectory model was identified with a no-risk, low-risk, high-risk, early-onset increasing risk, and late-onset increasing risk group. The likelihood of ever experiencing permanent disability or receiving Social Security Disability Insurance between the ages of 25 and 64 years differed across the trajectories with the early-onset and high-risk groups having the greatest likelihood and the no-risk trajectory having the lowest likelihood of work disability. Productivity loss trajectories are highly related to work disability outcomes.

A New Method to Classify Injury Severity by Diagnosis: Validation Using Workers’ Compensation and Trauma Registry Data

Acute work-related trauma is a leading cause of death and disability among U.S. workers. Existing methods to estimate injury severity have important limitations. This study assessed a severe injury indicator constructed from a list of severe traumatic injury diagnosis codes previously developed for surveillance purposes. Study objectives were to: (1) describe the degree to which the severe injury indicator predicts work disability and medical cost outcomes; (2) assess whether this indicator adequately substitutes for estimating Abbreviated Injury Scale (AIS)-based injury severity from workers' compensation (WC) billing data; and (3) assess concordance between indicators constructed from Washington State Trauma Registry (WTR) and WC data. WC claims for workers injured in Washington State from 1998 to 2008 were linked to WTR records. Competing risks survival analysis was used to model work disability outcomes. Adjusted total medical costs were modeled using linear regression. Information content of the severe injury indicator and AIS-based injury severity measures were compared using Akaike Information Criterion and R(2). Of 208,522 eligible WC claims, 5 % were classified as severe. Among WC claims linked to the WTR, there was substantial agreement between WC-based and WTR-based indicators (kappa = 0.75). Information content of the severe injury indicator was similar to some AIS-based measures. The severe injury indicator was a significant predictor of WTR inclusion, early hospitalization, compensated time loss, total permanent disability, and total medical costs. Severe traumatic injuries can be directly identified when diagnosis codes are available. This method provides a simple and transparent alternative to AIS-based injury severity estimation.

Capturing complexity in work disability research: application of system dynamics modeling methodology

Background: Work disability (WD) is characterized by variable and occasionally undesirable outcomes. The underlying determinants of WD outcomes include patterns of dynamic relationships among health, personal, organizational and regulatory factors that have been challenging to characterize, and inadequately represented by contemporary WD models. Method: System dynamics modeling (SDM) methodology applies a sociotechnical systems thinking lens to view WD systems as comprising a range of influential factors linked by feedback relationships. SDM can potentially overcome limitations in contemporary WD models by uncovering causal feedback relationships, and conceptualizing dynamic system behaviors. It employs a collaborative and stakeholder-based model building methodology to create a visual depiction of the system as a whole. SDM can also enable researchers to run dynamic simulations to provide evidence of anticipated or unanticipated outcomes that could result from policy and programmatic intervention. Discussion: SDM may advance rehabilitation research by providing greater insights into the structure and dynamics of WD systems while helping to understand inherent complexity. Challenges related to data availability, determining validity, and the extensive time and technical skill requirements for model building may limit SDM's use in the field and should be considered.Implications for RehabilitationContemporary work disability (WD) models provide limited insight into complexity associated with WD processes.System dynamics modeling (SDM) has the potential to capture complexity through a stakeholder-based approach that generates a simulation model consisting of multiple feedback loops.SDM may enable WD researchers and practitioners to understand the structure and behavior of the WD system as a whole, and inform development of improved strategies to manage straightforward and complex WD cases.

Is temporary employment a risk factor for work disability due to depressive disorders and delayed return to work? The Finnish Public Sector Study

Research on temporary employment as a risk factor for work disability due to depression is mixed, and few studies have measured work disability outcome in detail. We separately examined the associations of temporary employment with (i) the onset of work disability due to depression, (ii) the length of disability episodes, and (iii) the recurrence of work disability, taking into account the possible effect modification of sociodemographic factors. We linked the prospective cohort study data of 107 828 Finnish public sector employees to national registers on work disability (>9 days) due to depression from January 2005 to December 2011. Disability episodes were longer among temporary than permanent employees after adjustment for age, sex, level of education, chronic somatic disease, and history of mental/behavioral disorders [cumulative odds ratio (COR) 1.37, 95% confidence interval (95% CI) 1.25-51). The association between temporary employment and the length of depression-related disability episodes was more pronounced among participants with a low educational level (COR 1.95, 95% CI 1.54-2.48) and older employees (>52 years; COR 3.67, 95% CI 2.83-4.76). The association was weaker in a subgroup of employees employed for ≥ 50% of the follow-up period (95% of the original sample). Temporary employment was not associated with the onset or recurrence of depression-related work disability. Temporary employment is associated with slower return to work, indicated by longer depression-related disability episodes, especially among older workers and those with a low level of education. Continuous employment might protect temporary employees from prolonged work disability.

The joint contribution of pain and insomnia to sickness absence and disability retirement: A register–linkage study among Norwegian and Finnish employees

Pain and insomnia are both independently associated with work disability. Although pain and insomnia often co-occur, their joint associations with subsequent sickness absence and disability retirement have not been studied. We aimed to examine these associations in two prospective occupational cohorts while considering key covariates. Norwegian Hordaland Health Study (n = 6892, 59% women) and Finnish Helsinki Health Study (n = 6060, 78% women) data were used. Those with only pain, only insomnia or both conditions at baseline were compared with those with no pain and no insomnia. Work disability outcomes were derived from national and employers' register data. Medically certified sickness absence spells lasting 2 weeks or more and all-cause disability retirement were examined. Register-based follow-up was 4 years for sickness absence and 5 years for disability retirement. Covariates were sex, age, marital status, education, smoking, alcohol use, body mass index and blood pressure. Poisson and Cox regression models were fitted. Both pain and insomnia were associated with subsequent sickness absence and disability retirement, but the associations were stronger for those reporting co-morbid pain and insomnia with support for a synergistic interaction effect, particularly regarding disability retirement. The associations were largely similar in both cohorts and remained after full adjustments. This study is the first to report the separate and combined effects of pain and insomnia on objective health outcomes. Common patterns observed in two separate cohorts suggest that the combination of pain and insomnia might be particularly relevant for subsequent disability retirement.

Predicting work-related disability and medical cost outcomes: A comparison of injury severity scoring methods

IntroductionAcute work-related trauma is a leading cause of death and disability among U.S. workers. Occupational health services researchers have described the pressing need to identify valid injury severity measures for purposes such as case-mix adjustment and the construction of appropriate comparison groups in programme evaluation, intervention, quality improvement, and outcome studies. The objective of this study was to compare the performance of several injury severity scores and scoring methods in the context of predicting work-related disability and medical cost outcomes. MethodsWashington State Trauma Registry (WTR) records for injuries treated from 1998 to 2008 were linked with workers’ compensation claims. Several Abbreviated Injury Scale (AIS)-based injury severity measures (ISS, New ISS, maximum AIS) were estimated directly from ICD-9-CM codes using two software packages: (1) ICDMAP-90, and (2) Stata's user-written ICDPIC programme (ICDPIC). ICDMAP-90 and ICDPIC scores were compared with existing WTR scores using the Akaike Information Criterion, amount of variance explained, and estimated effects on outcomes. Competing risks survival analysis was used to evaluate work disability outcomes. Adjusted total medical costs were modelled using linear regression. ResultsThe linked sample contained 6052 work-related injury events. There was substantial agreement between WTR scores and those estimated by ICDMAP-90 (kappa=0.73), and between WTR scores and those estimated by ICDPIC (kappa=0.68). Work disability and medical costs increased monotonically with injury severity, and injury severity was a significant predictor of work disability and medical cost outcomes in all models. WTR and ICDMAP-90 scores performed better with regard to predicting outcomes than did ICDPIC scores, but effect estimates were similar. Of the three severity measures, maxAIS was usually weakest, except when predicting total permanent disability. ConclusionsInjury severity was significantly associated with work disability and medical cost outcomes for work-related injuries. Injury severity can be estimated using either ICDMAP-90 or ICDPIC when ICD-9-CM codes are available. We observed little practical difference between severity measures or scoring methods. This study demonstrated that using existing software to estimate injury severity may be useful to enhance occupational injury surveillance and research.

Risk factors for work disability associated with arthritis and other rheumatic conditions

In our first columnin this series on arthritis and em-ployment, we reviewed the evidence showing that thevarious forms of arthritis and other rheumatic condi-tions are associated with a substantial amount of workdisability.Whilemedicaltreatmentisofcoursethema-jor intervention for work disability, curative or evensubstantially effective treatment is often not availableleaving many people with arthritis continuing to expe-rience arthritis-related work limitations [1]. If factorsthat increase people’s risk for work disability – i.e.,work disability risk factors – can be identified and arepotentially modifiable, these factors would help guidethe development of interventions to enhance people’swork participation and performance.The purpose of this article is to review the litera-ture on risk factors for arthritis and other rheumaticcondition-related work disability. We reviewed stud-ies providing quantitative or qualitative data on riskfactors for any type of work disability outcome, e.g.,premature work cessation and productivity limitation.Productivity limitation includes absenteeism and pre-senteeism, the latter being reduced capacity to workwhile at work due to health.Risk factor studies have primarily been conductedusing samples of persons with a particular rheumatic

Work disability after road traffic injury in a mixed population with and without hospitalisation

BackgroundStudies addressing work disability after road traffic injury are generally aimed at seriously injured hospital patients, and less is known about the disability burden associated with injuries not requiring hospitalisation. The aim of this study was to describe the distribution and determinants of work disability outcomes for patients with musculoskeletal and orthopaedic traffic injuries, including those not sufficiently severe to require hospitalisation. MethodsPersons injured in road traffic accidents in 2005–2007 claiming compensation via the Transport Accident Commission (Victoria, Australia) were included if they had compensated time off work, and their most serious injury was musculoskeletal or orthopaedic (n=5970). Work disability outcomes were determined from income compensation payments over 17 months following the accident. Logistic regression models were used relating demographic and injury characteristics to work disability. ResultsOf the injuries, 59% required hospitalisation; 15% required hospitalisation of >1 week. Long-term work disability was common with 32% of injuries resulting in work disability ≥6 months after the accident. The duration of work disability increased markedly with length of hospital stay. Those with no hospital stay accounted for 27% of all work disability days; those with ≤7 days in hospital (including no hospital stay) accounted for 71%. Female sex, age ≥35 years and early opioid prescriptions were also risk factors for work disability ≥6 months after the accident. ConclusionThe majority of work disability days were among patients with one week or less in hospital. Because (short) hospitalisation was relatively common after traffic accidents, the relative work disability burden of non-hospitalised injury is not as great as in a mixed injury aetiology population.