Does gradually returning to work improve time to sustainable work after a work-acquired musculoskeletal disorder in British Columbia, Canada? A matched cohort effectiveness study

Abstract

ObjectiveThis study investigates if gradual return to work (GRTW) is associated with full sustainable return to work (RTW) for seriously injured workers with a musculoskeletal disorder (MSD), in British Columbia, Canada.MethodsThis is an effectiveness study using a retrospective cohort study design. Accepted workers’ compensation lost-time claims were extracted for workers with an MSD who were on full work disability for at least 30 days, between 2010 and 2015 (n=37 356). Coarsened exact matching yielded a final matched cohort of 12 494 workers who experienced GRTW at any point 30 days post-injury and 12 494 workers without any GRTW. The association between GRTW and sustainable RTW through to end of 12 months was estimated with multivariable quantile regression.ResultsWorkers who were provided with GRTW experienced more time-loss days until sustainable RTW between the 2nd and 5th months after the first time-loss day (<50th quantile of time loss), but less time-loss days until sustainable RTW between the 6th and 12th months of work disability (70th quantile of time loss), with the largest effect for women, workers with soft-tissue injuries and workers in the manufacturing or trades sector (all in the 60th and 70th percentile, after 6–7 months of time loss).ConclusionsFor seriously injured workers with at least 30 days of disability due to a work-acquired MSD, the effect of GRTW becomes apparent at longer disability durations (more than 6 months), with larger beneficial effects for women, workers with soft-tissue injuries and for trade and manufacturing sectors.

Differences in Work Disability Duration for Immigrants and Canadian-Born Workers in British Columbia, Canada

“…The findings of differences in work disability duration for immigration classification by sex/gender are more complex. Studies that have examined disability duration and sex/gender differences have been mixed [49,53,69], and only one to date has differentiated by immigration status, measured as length of time in Canada [6]. In this one previous study, recent immigrant men (<10 years in Canada) displayed a longer disability duration while recent immigrant women had disability durations closer to Canadian-born women.…”

“…Quantile regression models [52] were used to estimate predicted work disability days for immigrant workers compared to Canadian-born workers at the 25th, 50th and 75th percentiles of the disability days distribution. Quantile regression is an appropriate method when the outcome variable is skewed and allows for the investigation of different effects for those who have longer disability durations as unique sub-groups [53,54]. The models for each injury cohort were adjusted for all confounders and stratified by sex/gender as best practice for health-related research [55,56].…”

“…A sensitivity analysis using Cox regression that examined the relationship between immigration classification and time to sustained RTW outcome (return to work, full duties, and with no further disability days) was also performed. This analysis was done to see if there was a difference in effect between work disability days on claim versus time to sustained RTW as two indicators of disability [53]. This approach used piecewise models [57] to calculate hazard ratios (HR) from the first short-term disability day to sustained RTW within 30, 60, 90 and 365 days in order to handle any potential non-proportionality.…”

“…From a policy perspective, the findings provide a signal to workers' compensation and occupational health organizations of the potential need for tailored disability management efforts for immigrant workers, specifically family member and refugee/other classification immigrant women. This can be provided in the form of a gradual return to work (temporarily changing a worker's duties, hours and/or days of work) that has been shown to reduce work disability duration for workers with longer-term claims [53]. Programs and policies that take into account underlying contexts and the drivers of health and safety inequalities for immigrant workers are also needed to facilitate access to and implementation of recovery and rehabilitation services.…”

“…Quantile regression as the main analytic methodology allowed us to examine work disability duration at shorter and longer points of the disability distribution, is appropriate for skewed distributions and is considered an intuitive and interpretable method for direct effect estimates [53].…”