Risk of work loss due to illness or disability in patients with osteoarthritis: a population-based cohort study

Objectives. To estimate the risk of work loss due to illness or disability in a cohort of employed persons with OA compared with matched non-OA individuals. Methods. We performed a population-based cohort analysis using the last six cycles of the Canadian longitudinal National Population Health Survey from 2000 to 2010. OA cases and up to four age- and sex-matched non-OA individuals were selected. Discrete time hazard regression models were used to estimate the hazard of work loss due to illness or disability. To analyse the effect of a self-reported OA measure on the outcome, we performed a sensitivity analyses for case selection. Results. From 7273 employed individuals between the ages of 20 and 70 years in the National Population Health Survey, 659 OA cases were selected and matched to 2144 non-OA individuals. The proportion of OA cases who experienced work loss due to illness or disability during the follow-up period was 12.6%, compared with 9.3% for non-OA individuals (P < 0.001). OA cases had a 90% [hazard ratio (HR) 1.90 (95% CI 1.36, 3.23)] higher hazard of work loss due to illness or disability compared with their matched non-OA individuals after adjusting for sociodemographic, health and work-related status. The adjusted HRs were 1.61 (95% CI 1.13, 2.30) and 2.04 (95% CI 1.74, 4.75) for females and males, respectively. Conclusion. OA is independently associated with an increased risk of work loss due to illness or disability. Given the high prevalence of OA in the population of working age, future research may wish to investigate ways to improve occupational participation among OA patients.