Using Ecological Momentary Assessment to Examine the Effects of Duty Status on Acute Stress and Tiredness in Firefighters A Pilot Study

Objective: Characterize firefighters' acute stress and tiredness by duty status (ie, "off night/day," "on night/day"). Methods: Thirty nine career firefighters completed three, eight-day smartphone-based ecological momentary assessment periods with seven surveys per day assessing stress and tiredness. Mixed-effects location scale models examined duty status effects on stress and tiredness. Results: Firefighters' lowest stress and tiredness levels were when off-duty (beta = 16.27 and beta = 24.71, respectively) and their highest levels were when on-duty (beta = 24.47 and beta = 32.18, respectively). Within-subject effects of duty status accounted for a larger proportion of variability in stress and tiredness for all duty types, except for stress when "on-duty night/off-duty day." Conclusions: Firefighters had more similar stress and tiredness outcomes when they were on-duty and less similar outcomes when off-duty. This could be due to firefighters having more similar experiences when they are on- versus off-duty.