The relationship of unions to prevalence and claim filing for work-related upper-extremity musculoskeletal disorders.

BACKGROUND Unionization has been found to be related to higher filing of workers' compensation (WC) claims, but the extent of the relationship and the relationships to other variables have not been previously reported. METHODS Telephone interviews were conducted with both a population-based and WC-based samples of musculoskeletal disorder (MSD) cases. RESULTS Workers at unionized facilities were 5.7 times (95% CI 2.5-13.1) more likely to file a claim for WC, despite a comparable rate of MSD cases. Higher filing was also associated with several measures of MSD severity (1.8-14.1 odds ratios), economic sector (OR = 10.1 for manufacturing), hourly (vs. salary) wages (OR = 2.6), and for having a personal physician (OR = 2.5). Unions appeared to have a protective effect on social effects of work-related MSD. CONCLUSIONS Unions appear to improve filing of work-related MSD, particularly for less severe conditions. The higher filing does not appear to be a case of "moral hazard," but rather improved and earlier reporting, as is advocated by early intervention approaches to reducing MSD.