Other individual precautions, such as installing video cameras and warning signs or increasing visibility of the work area from outside, also might help, UNC public health and medicine investigators say, but their study uncovered no evidence of that.
“Homicide is the second leading cause of death in the workplace in the United States after motor vehicle crashes with an average of 20 fatal assaults on workers every week,” said Dr. Dana Loomis, professor of epidemiology. “We did our study to try to learn what steps can make a difference in reducing the toll.”
A report on the findings, the first of their kind, appears in the Feb. 27 issue of the Journal of the American Medical Association. Besides Loomis, authors are Dr. Stephen W. Marshall, research assistant professor; Susanne H. Wolf, research associate; Dr. Carol W. Runyan, director of the UNC Injury Prevention Research Center; and Dr. John D. Butts, N.C. chief medical examiner and professor of pathology and laboratory medicine.
Using statewide data from the Office of the Chief Medical Examiner, the team identified all 105 cases of murder on the job in North Carolina between Jan. 1, 1994, and March 31, 1998, and also, as controls, found 210 similar, randomly selected workplaces where homicides had not occurred. Detailed interviews with managers of the businesses, police and others -- along with computerized analyses and comparisons of workplace characteristics -- produced evidence of steps promoting worker safety.
“Among environmental interventions, strong and consistent reductions in the risk of a worker being killed on the job were associated with bright exterior lighting,” Loomis said. “Among administrative interventions, the largest beneficial effect was for staffing practices that prevented workers being alone at night.”
Keeping doors closed during working hours also was associated with reduced risk, but that finding was not statistically significant, he said. Combinations of five or more administrative measures appeared to lower risk levels significantly.
“Eliminating solo work at night could reduce the risk of homicide for workers by up to 70 percent,” Loomis said. “Keeping doors closed and using bright exterior lighting or combinations of administrative interventions also appear to be beneficial, but there was no evidence of effectiveness for a number of other recommended measures individually.”
Requiring two or more employees in stores open at night, as Florida does, is controversial among store owners since it is expensive, he said. The new research suggests that the added cost may save lives.
“Measures designed to prevent robberies have been widely used since the 1970s, but this is the first study to directly evaluate whether those measures also protect workers against violence,” Loomis said.
With the exception of closed doors, alarms and bright exterior lighting, efforts to make businesses unattractive targets for robbery tended to have little effect on the risk of death resulting from domestic and other disputes involving workers, the authors found.
The National Center for Injury Prevention and Control, a branch of the Centers for Disease Control and Prevention, supported the research through a grant to the UNC Injury Prevention Research Center.
Note: Loomis can be reached at (919) 966-7433 or Dana_Loomis@unc.edu
Between Feb. 27 and March 3, Runyan at (919) 966-3916 is the best source.
School of Public Health Contact: Lisa Katz, (919) 966-7467
News Services Contact: David Williamson, (919) 962-8596
Journal
JAMA