Table 5.

Adjusted odds ratios for sleep disturbances and life quality impairment by vitamin D deficiency.

Sleep Disturbances and Life Quality Impairment	Vitamin D Deficiency
	Daytime Workers (n = 432)		Night-Shift Workers (n = 412)
	OR (95% CI)	P	OR (95% CI)	P
Self-reported poor sleep quality (PSQI > 5)	0.78 (.50–1.22)	.281	.98 (.55–1.74)	.934
Excessive daytime sleepiness (ESS > 10)	2.20 (1.30–3.74)	.003	.88 (.54–1.42)	.592
Total sleep time ≤ 6 hours*	3.07 (1.51–6.26)	.002	1.10 (.32–3.74)	.879
Sleep efficiency ≤ 85%*	1.62 (.86–3.06)	.137	.76 (.35–1.64)	.489
Wake after sleep onset ≥ 30 min*	0.61 (.22–1.73)	.352	.47 (.02–13.43)	.659
QOL-BREF-psychological health score < 60†	1.83 (1.07–3.29)	.028	1.07 (.60–1.91)	.818
QOL-BREF-social relationship score < 60†	1.78 (1.10–2.88)	.020	1.06 (.60–1.88)	.844

Multiple logistic regression analysis was performed controlling for age, sex, body mass index, current smoking status, drinking habits, caffeine consumption, physical activity, medical comorbidities, MEQ scores and HADS scores. *Analysis was performed for 150 night-shift workers and 203 daytime workers. †Analysis was performed after controlling for age, sex, body mass index, current smoking status, drinking habits, physical activity, medical comorbidities, CD-RISC = Connor–Davidson resilience scale, CI, confidence interval, ESS = Epworth Sleepiness Scale, FSS = Fatigue Severity Scale, HADS = Hospital Anxiety and Depression Scale, MEQ = Morningness–Eveningness Questionnaire, OR = odds ratio, PSQI = Pittsburgh Sleep Quality Index, QOL-BREF = Quality of Life Scale Abbreviated Version.