Table 2.

ORs and 95% CIs for insomnia symptoms and sleep duration by nighttime traffic noise in the crude and adjusted models.

Noise level (dB)	Any insomnia symptom	Difficulties falling asleep	Frequently waking up during the night	Waking up too early in the morning	Nonrestorative sleep	Short sleep duration (< 7 hr)
Model 1a
≤ 45 (reference)
45.1–50	0.95 (0.84, 1.07)	1.01 (0.86, 1.20)	0.98 (0.86, 1.10)	1.03 (0.90, 1.19)	0.97 (0.86, 1.11)	0.99 (0.86, 1.14)
50.1–55	0.99 (0.84, 1.16)	1.04 (0.83, 1.30)	1.03 (0.88, 1.22)	0.88 (0.72, 1.06)	0.96 (0.81, 1.14)	0.95 (0.79, 1.15)
> 55	1.16 (0.95, 1.46)	0.83 (0.61, 1.13)	1.00 (0.81, 1.23)	1.10(0.87, 1.39)	1.15 (0.92, 1.43)	1.11 (0.86, 1.43)
Model 2b
≤ 45 (reference)
45.1–50	0.95 (0.84, 1.07)	1.02 (0.86, 1.21)	0.98 (0.86, 1.11)	1.04 (0.90, 1.20)	0.98 (0.86, 1.12)	1.00 (0.86, 1.15)
50.1–55	0.97 (0.83, 1.14)	1.02 (0.81, 1.28)	1.02 (0.86, 1.20)	0.85 (0.69, 1.03)	0.96 (0.80, 1.14)	0.98 (0.81, 1.18)
> 55	1.15 (0.93, 1.42)	0.81 (0.59, 1.12)	1.01 (0.81, 1.25)	1.11 (0.87, 1.41)	1.15 (0.92, 1.44)	1.14 (0.88, 1.48)
Model 3c
≤ 45 (reference)
45.1–50	0.95 (0.84, 1.08)	1.06 (0.88, 1.27)	0.97 (0.85, 1.10)	1.04 (0.89, 1.21)	0.99 (0.86, 1.14)	0.98 (0.85, 1.14)
50.1–55	1.00 (0.84, 1.19)	1.05 (0.82, 1.34)	1.02 (0.85, 1.22)	0.85 (0.69, 1.05)	1.01 (0.84, 1.23)	0.99 (0.81, 1.22)
> 55	1.32 (1.05, 1.65)	0.83 (0.59, 1.17)	1.12 (0.88, 1.41)	1.24 (0.96, 1.61)	1.29 (1.01, 1.65)	1.12 (0.86, 1.47)
aCrude model. bModel adjusted for age, sex, occupational status, and residence size. cModel adjusted for age, sex, occupational status, residence size, marital status, chronic disease, trait anxiety, and neighborhood socioeconomic disadvantage and population density.