Initial return to work and long-term employment patterns: associations with work-related permanent impairment and with participation in workers' compensation-based return-to-work programs

Background: Roughly 10% of injured workers experience work injuries that result in permanent impairment and a permanent partial disability (PPD) award. This study aimed to characterize and quantify long-term employment outcomes for injured workers, by the degree of whole body impairment (WBI) and by participation in several workers' compensation (WC)-based return-to-work (RTW) programs. Methods: A retrospective cohort of 43,968 Washington State workers were followed for up to 10 years after WC claim closure (2009-2017). Degree of impairment was classified as: (1) no PPD award, (2) PPD award with WBI < 10%, or (3) PPD award with WBI = 10%. State wage files were used to construct employment outcomes for regression, modeling: (1) time to first RTW, (2) time to first RTW interruption, (3) RTW volatility, and (4) employment gaps. Results: Wage patterns and employment outcomes differed significantly by the degree of impairment. Compared to other workers, workers with WBI = 10% had delayed RTW, shorter average times to first RTW interruption, and higher rates of both RTW interruptions and quarters without wages. Time to first RTW averaged over a year, increasing with the degree of impairment. About 9% overall-and 27% of workers with =10% WBI-had no observed wages after claim closure. In adjusted models, workers with WBI = 10% had significantly poorer employment outcomes, compared to workers with no PPD award (p < 0.001). Conclusions: State wage files provide an efficient approach to identifying RTW patterns. Workers with permanent impairment were at substantially higher risk of poor employment outcomes. WC-based RTW programs may promote better employment outcomes.