Table 3.

Relationship between work-related factors and insomnia

Variables	Model 1	Model 2	Model 3
Type of job
Administrative	(Reference)	(Reference)	(Reference)
Fire suppression	1.725 (1.264–2.354)	2.176 (1.500–3.158)	2.456 (1.461–4.128)
EMS/rescue	1.735 (1.270–2.371)	2.093 (1.443–3.036)	1.871 (1.105–3.167)
Others	1.583 (1.148–2.182)	1.844 (1.258–2.703)	1.968 (1.163–3.331)
Work schedule
Day work	(Reference)	(Reference)	(Reference)
3-day cycle	1.177 (0.818–1.692)	1.388 (0.906–2.128)	0.847 (0.500–1.434)
9-day cycle	1.448 (1.071–1.958)	1.444 (1.010–2.064)	0.858 (0.536–1.374)
21-day cycle	1.338 (1.041–1.721)	1.513 (1.122–2.038)	0.802 (0.524–1.227)
Others	1.530 (1.064–2.202)	1.618 (1.052–2.487)	0.892 (0.528–1.506)
Frequency of emergency events, times per week*
< 5	(Reference)	(Reference)	(Reference)
5–9	1.357 (1.098–1.678)	1.345 (1.056–1.715)	1.231 (0.960–1.580)
10–19	1.708 (1.400–2.083)	1.571 (1.248–1.978)	1.453 (1.142–1.848)
20–39	2.173 (1.757–2.687)	1.896 (1.479–2.431)	1.816 (1.388–2.377)
≥ 40	2.767 (1.999–3.829)	2.421 (1.660–3.532)	2.340 (1.570–3.486)
Frequency of off-duty work, times per month*
< 1	(Reference)	(Reference)	(Reference)
1–2	1.555 (1.333–1.815)	1.307 (1.093–1.562)	1.252 (1.042–1.504)
3–4	2.135 (1.688–2.700)	1.540 (1.172–2.024)	1.477 (1.115–1.955)
≥ 5	2.569 (1.828–3.609)	1.421 (0.938–2.151)	1.563 (1.022–2.390)

The data are presented as odds ratios (95% confidence interval). EMS means emergency medical service. Model 1 adjusts for age and sex; model 2 adjusts for demographic characteristics (age, sex, BMI, education, income, marital status, smoking, alcohol consumption, caffeine intake, and exercise), and comorbidities (fatigue, depression, anxiety, and PTSD); model 3 adjusts for the demographic characteristics, comorbidities, and work-related characteristics (type of job, employment period, work schedule, frequency of emergency events and off-duty work). *p-value for trend < 0.05 in model 3