Abstract
Objective: The aim of this study was to determine the role of obesity on the association between sleep and on-duty injury among male career firefighters. Methods: Data on 1419 male career firefighters for this cross-sectional study came from two firefighter cohorts from 2008 to 2013. On-duty injury within the past 6 to 12 months was the dependent variable and getting enough sleep was the independent variable. A multivariable, mixed effect logistic regression model stratified by body mass index (BMI) categories was created to examine the presence of effect measure modification. Results: Only obese firefighters who did not get enough sleep were twice as likely to have an on-duty injury than those who got enough sleep. This association was not significant among normal or overweight firefighters. Conclusions: Future studies into on-duty injury and sleep should examine body composition as an effect modifier among career firefighters.