Table 3.

Parameters of sleep disturbance of the population by residential area

	Area*
Sleep disturbance parameters	noisy	quiet	P
Duration of night sleep (h)	6.9 ± 1.2	7.2 ± 2.0	0.100†
Difficulty with falling asleep (grade, mean±SD)	2.1 ± 0.8	1.9 ± 0.7	0.023‡
Time needed to fall asleep (grade, mean±SD)	1.9 ± 0.9	1.8 ± 0.9	0.892‡
Sleeping by open window (%)	52.6	93.7	<0.001§
Waking up at night (%)	60.1	38.8	<0.001§
Difficulty with falling back to sleep (%)	35.7	23.2	0.024§
Sleep quality (grade, mean±SD)	3.4 ± 0.9	3.6 ± 0.9	0.015‡
Tiredness after sleep (grade, mean±SD)	2.9 ± 0.8	2.6 ± 0.8	0.005‡
Use of sleeping pills (grade, mean±SD)	1.2 ± 0.7	1.2 ± 0.6	0.963‡

*Noisy area >65 dB(A); quiet area <55 dB(A).

†Student's t test.

‡Mann-Whitney's U-test.

§χ² test.