Risk factors for work-related assaults on nurses

Work-related homicides have been the subject of considerable study, but little is known about nonfatal violence and relevant risk factors.

We surveyed 6300 Minnesota nurses who were selected randomly from the 1998 licensing database and determined their employment and occupational violence experience. In a nested case-control study, we examined environmental exposures and physical assault. Cases of assault in the previous 12 months and controls randomly selected from assault-free months were surveyed about prior-month exposures.

After adjustment by multiple logistic regression, incidence of physical assault was 13.2 per 100 persons per year (95% confidence interval = 12.2-14.3). Among 310 cases and 946 control subjects, odds ratios for assault were increased: in nursing homes or long-term care facilities (2.6; 1.9-3.6), emergency departments (4.2; 1.3-12.8), and psychiatric departments (2.0; 1.1-3.7); in environments not "bright as daylight" (2.2; 1.6-2.8); and for each additional hour of shift duration (1.05; 0.99-1.11). Risks were decreased when carrying cellular telephones or personal alarms (0.3; 0.2-0.7).

These results may guide in-depth investigation of ways protective and risk factors can control violence against nurses.