Methods: The bunkroom intervention involved eliminating unnecessary alarms, optimizing room temperature for sleep hygiene, and reducing light for 6 weeks. Sleep quality was self-reported from 0 (poor) to 5 (good). Actigraph to the non-dominant wrist was applied to classify disturbed sleep. Disturbed sleep was defined as meeting 2 of the following 4 criteria: total sleep time less than 6 hours; total sleep latency greater than 30 minutes; sleep efficiency less than 85%; or, wake after sleep onset greater than 30 minutes. Actigraph was also used to measure the amount of time a firefighter was out of bed during their sleep window. BP was measured as the average of two readings taken 5-minutes apart with the firefighter in the sitting-up positon. HTN was defined as a BP greater than 130/85 mm Hg per 2017 AHA BP Guidelines. Lastly, we assessed firefighters’ compliance and measured their satisfaction with the intervention as a means to measure sustainability. Continuous variables were reported as mean ± standard deviation, and categorical variables as frequencies and percentages. Pre- and post-assessment were examined using paired t tests. Significance was set to 0.05 or less for a two-tailed test.
Results: Twenty-four firefighters enrolled in the study, but only 11 firefighters participated in post-test assessment due to department transfers (mean age= 42 ± 9.5 years; 95% male; 92% overweight or obese). Compliance to the intervention was mixed: temperature remained within the prescribed range (range 63 °F- 67 °F), light as measured by luminesce dropped significantly (p<0.05) but noise level changed minimally (p>0.05). Sleep quality significantly improved after the 6 weeks (p=0.007). Although not statistically significant, on average it took 5 fewer minutes for on-duty firefighters to fall asleep (18.2± 14.9 minutes vs 13.3 ± 8.2 minutes; p>0.05). 60% of the firefighters had disturbed sleep per wrist actigraph at baseline, and after the intervention 41% were classified as experiencing disturbed sleep (p>0.05) .The mean amount of time a firefighter was out of bed during their sleep window fell from 22.94± 39.6 minutes to 7.37± 20.1 minutes (p=0.01). The prevalence of HTN dropped from 37% to 11% (p<0.05). Firefighters self-reported willingness to adopt the intervention after the pilot study and reported overall satisfaction with the intervention.
Conclusions: In this small pilot study using an environmental modification intervention in the bunkroom of a firehouse, improvements in sleep quality were associated with a reduction in the prevalence of HTN among on-duty firefighters. Both disturbed sleep and HTN are highly prevalent problems among professional on-duty firefighters. Firefighters also reported willingness to adopt the intervention and were satisfied with the intervention. Given this environmental modification intervention does not require consistent and continuous commitment by firefighters to individually improve their sleep quality and reduce their BP, environmental modifications such as this may be powerful and sustainable.