Occupational injuries: comparing the rates of male and female postal workers.

To compare the injury rates of male and female postal workers, the authors reanalyzed data on a cohort of 2,337 new postal employees in Boston, Massachusetts, hired between 1986 and 1989. The analysis controlled for potential confounding by age, race, smoking status, and drug use. Using Cox proportional hazards models with time-dependent variables, the authors found that, compared with men, women had an increased relative risk for occupational injuries in each of the three largest job classifications: letter carrier, letter-sorting machine clerk, and mail handler. The relative risks were not constant over time. For letter carriers and letter-sorting machine clerks, the increased risks for women were noted only during the first year of employment (relative risk (RR) = 1.93, 95% confidence interval (CI) 1.40-2.67) and RR = 2.60, 95% CI 1.31-5.15, respectively). For mail handlers, the increased risks for women were noted only after the first year of employment (RR = 2.13, 95% CI 1.09-4.15). As the percentage of women in the work force increases, these results suggest the need for further research to define sex-specific injury risks and to devise prevention strategies.