The relationship between the pattern of shift work and sleep disturbances in Korean firefighters

Abstract

Purpose Sleep disturbances are prevalent in firefighters, but the relationship between patterns of shift work and sleep disturbances has not yet been investigated. Here, this relationship has been evaluated in Korean firefighters. Methods A cross-sectional study was conducted using an online questionnaire, which captured demographic, psychosocial and work-related characteristics. Sleep disturbance was assessed using the insomnia severity index (ISI). The relationship between insomnia and work-related factors (including type of shift work and the frequency of emergency events and off-duty work which means overtime work on off days) was analyzed. Results A total of 9810 firefighters completed the survey, representing approximately 21.5% of all Korean firefighters; data from 9738 subjects were included in the analysis. All firefighter roles were significantly associated with insomnia; the odds ratio (OR) was 2.456 (95% confidence interval [CI] 1.461-4.128) for fire suppression and 1.871 (95% CI 1.105-3.167) for the emergency medical services and rescue. However, the pattern of shift work did not show a statistically significant relationship. The OR increased along with the frequency of emergency events and off-duty work (p value for trend < 0.05). Conclusions This study found a significant association between the frequency of emergency and off-duty work and insomnia in Korean firefighters, whereas the pattern of shift work showed no significant relationship. Therefore, measures to reduce the frequency of emergency and off-duty work are required to prevent sleep disturbances in firefighters.

Effects of Occupational and Leisure-Time Physical Activities on Insomnia in Korean Firefighters

“…In addition, the insomnia risk was significantly increased in the case of feeling much of physical burden during firefighting work (high subjective OPA) and if the frequency of occupational activities was ≥5 times a week. These results are consistent with previous studies according to which a high level of OPA and working long hours significantly increased the sleep disturbance risk [ 11 , 21 , 32 ].…”

“…Previous studies have shown that the shiftwork itself is not only associated with high OPA [ 21 , 32 ], but can also cause insomnia by disrupting the circadian rhythm [ 33 ]. However, the results of this study show that shift work does not significantly affect insomnia.…”

“…The reason for this may be that the analysis was based only on the frequency being more than or less than 3 times a month. In fact, Jang et al reported that the sleep disturbance risk was higher in firefighters whose frequency of off-duty work was 1-2 times a month, 3-4 times a month, or ≥5 times a month, compared to fire-fighters whose frequency of off-duty work was <1 a month, and reported that the result of a trend analysis was also significant [ 21 ]. If the frequency of off-duty work had been analyzed in more detail or as a continuous variable in this study, other results would have been derived.…”

“…However, they considered the effect of only LTPA (not OPA) on insomnia. Fire-fighters are already exposed to a very high level of OPA since they have to wait for an occupational activity such as large-scale fires or accidents at any time, even in during an off-duty day [ 21 ]. Considering these, we think that the results of this study were somewhat different from previous studies that targeted the general population.…”

“…It was reported that the risk of suffering from insomnia was more frequent [ 20 ] in shift-work firefighters compared to day-work firefighters. Furthermore, there was a strong association between the frequency of emergency and off-duty work and insomnia in Korean firefighters [ 21 ]. However, these studies only included OPA in their analysis.…”