The health care industry is one of the most dangerous industries, ranking with construction, trucking, and meatpacking in nonfatal injury rates.1 Because of the growing elderly population, nursing homes have become major care providers to the elderly within the health care industry.2 About 1.5 million elderly and disabled Americans reside in nursing homes, and nursing assistants provide the majority of their care.3 second among all industries.4 Nursing homes are among the top 10 industries for musculoskeletal problems, which is the major cause of worker absenteeism, workers’ compensation claims, and worker injury and illness.1^,4^–7 Higher rates of musculoskeletal injury have been reported among nursing home workers compared with rates among workers in other occupations.8^,9

Nursing home employees working in direct-care facilities perform many physically taxing activities, such as lifting heavy loads, working in awkward postures, and transferring residents.6^,10^–14 Additionally, manipulating the technology that supports patient care is physically straining. The increased worker injury rates likely result from increased exposure to hazardous conditions and diminished recovery time between exposures.15

Worker injuries in health care institutions associated with staffing levels and skill mix have been previously examined. Because health care institutions have been required to perform more efficiently, the resultant changes are lower staffing levels and higher patient loads, both of which have been shown to increase worker injury. In a study of 12 hospitals in the Minneapolis–St Paul, Minnesota, area that used data from 1990 to 1994, Shogren and Calkins16 found that when registered nurse (RN) positions were decreased by 9%, work-related illnesses and injuries among nurses increased by 65%. A review of the impact of staffing on health care by the Institute of Medicine noted that there is empirical evidence that shows back injuries among nurses are associated with staffing levels.17 Although the extent of worker injuries among resident care staff in nursing homes has been documented,18^–20 there have been few studies about the association between injuries and staffing.

The occurrence of these injuries has important implications for staff retention. Owen and Garg21 found that 20% of nurses who reported they had back pain said they had made at least 1 job change in order to decrease the number of nursing home residents that had to be lifted and transferred. Turnover among unlicensed personnel was even higher,22 with 23% annual turnover reported among nursing assistants in one facility.23 In a statewide survey of nursing assistants, 30% reported they planned to quit their jobs.24

We used an ecological design that was based on administrative data to examine the association between staffing rates and worker injuries. To do this, we analyzed the association between staffing variables (total nursing care hours per resident day) and adverse worker outcomes (reported worker injuries) at the institutional level. Analyses were also adjusted for resident acuity, profit status, nursing home size, and availability of nurse aide training.