Risk factors for physical assault. State-managed workers' compensation experience

The estimation of incidence and evaluation of risk factors associated with nonfatal occupational assault injuries have rarely been documented in a statewide population context. A state-managed workers' compensation system can provide estimates of incidence of such injuries and allow evaluation of risk factors.

Using claims data from the state-managed West Virginia Workers' Compensation, the incidence rates of workplace injuries resulting from physical assault were estimated for the period 1997-1999. Data on potential risk factors were obtained from the claim-related electronic data files, and the risk associated with each factor was assessed using proportional injury ratios (PIRs).

During the study period, 2122 compensated injuries were associated with workplace violence. The incidence of assault injuries was 108.2 cases per 100,000 employee years. Women sustained a higher incidence than men. Healthcare workers, public safety workers, and teachers accounted for almost 75% of all assault injuries. Workers in these occupations also differed from each other with regard to seasonality and timing of assault, perpetrator-victim relationship, and types of injury. Evidence of gender-occupation interaction indicated higher risk of assault injury in men compared to women across the three leading occupations. Nighttime work shifts were associated with greater risk of assault for female healthcare workers (PIR=1.8; 95% confidence interval, 1.09-2.87).

The healthcare sector sustained the bulk of assault injuries in West Virginia. Although the majority of healthcare-sector employees were women, the risk of assault injuries was higher in male employees. Risk factors and injury characteristics identified in this study, particularly for three high-risk occupations, should help develop strategies for preventing workplace violence. Protecting female healthcare workers on night-shift duty, especially in nursing home settings, appears to be an important target for intervention.