The impact of shift work on the risk and severity of injuries for hospital employees: an analysis using Oregon workers' compensation data.

BACKGROUND While past research on health care workers has found that shift work can lead to negative physiological and psychological consequences, few studies have assessed the extent to which it increases the risk of specific work-related injuries, nor quantified and compared associated types, severity and costs. AIMS This study aimed to derive and compare the rates, typologies, costs and disability time of injuries for various hospital worker occupations by day, evening and night shift. METHODS This study used Oregon workers' compensation claim data from 1990 to 1997 to examine the differences in hospital employee claims (n = 7717) by shift and occupation. Oregon hospital employee claim data, hospital employment data from Oregon's Labor Market Information System and shift proportion estimates derived from the Current Population Survey (CPS) were used to calculate injury rate estimates. RESULTS The injury rate for day shift per 10,000 employees was estimated to be 176 (95% CI 172-180), as compared with injury rate estimates of 324 (95% CI 311-337) for evening shift and 279 (95% CI 257-302), night shift workers. The average number of days taken off for injury disability was longer for injured night shift workers (46) than for day (38) or evening (39) shift workers. CONCLUSION Evening and night shift hospital employees were found to be at greater risk of sustaining an occupational injury than day shift workers, with those on the night shift reporting injuries of the greatest severity as measured by disability leave. Staffing levels and task differences between shifts may also affect injury risk.