Regional differences in the risk of insomnia symptoms among patients from general hospital outpatient clinics

Figures & data

Table 1 Comparison between rural and urban regions in basic sociodemographic and clinical characteristics

Characteristics	Total sample (n=4,399)		Rural region (n=2,631)		Urban region (n=1,768)		Statistics
	n	%	n	%	n	%	χ^2	df	P-value
Any type of insomnia symptoms	973	22.1	559	21.2	414	23.4	2.9	1	0.089
Females	2,896	65.8	1,746	66.4	1,150	65.0	0.8	1	0.366
Marital status							5.7	2	0.057
Unmarried	728	16.5	432	16.4	296	16.7
Married	3,528	80.2	2,127	80.8	1,401	79.2
Divorced/widowed	143	3.3	72	2.7	71	4.0
Employment status							234.9	2	<0.001
Employed	2,900	65.9	1,824	69.3	1,076	60.9
Unemployed	800	18.2	565	21.5	235	13.3
Retired	699	15.9	242	9.2	457	25.8
Live alone	415	9.4	267	10.1	148	8.4	3.9	1	0.048
Personal income ≥6,000 yuan/month	951	21.6	413	15.7	538	30.4	135.4	1	<0.001
No health insurance	2,825	64.2	1,967	74.8	858	48.5	316.7	1	<0.001
Family history of psychiatric disorders	217	4.9	109	4.1	108	6.1	8.7	1	0.003
Current drinking	959	21.8	564	21.4	395	22.3	0.5	1	0.476
Current smoking	594	13.5	376	14.3	218	12.3	3.5	1	0.062
Taking sleeping pills	257	5.8	125	4.8	132	7.5	14.2	1	<0.001
	Mean	SD	Mean	SD	Mean	SD	T	df	P-value
Age (years)	41.8	15.9	40.3	15.2	43.9	16.7	−7.4	4,397	<0.001
Education (years)	10.3	4.2	9.3	4.0	11.7	4.2	−19.1	4,397	<0.001

Notes: Values in bold are P<0.05 or P<0.001.

Table 2 Sociodemographic and clinical characteristics associated with insomnia symptoms by region

Characteristics	Rural region (n=2,631)					Urban region (n=1,768)
	Without insomnia symptoms (n=2,072)		With insomnia symptoms (n=559)		P-value	Without insomnia symptoms (n=1,354)		With insomnia symptoms (n=414)		P-value
	n	%	n	%		n	%	n	%
Females	1,361	65.7	385	68.9	0.157	864	63.8	286	69.1	0.049
Marital status					<0.001					<0.001
Unmarried	341	16.5	91	16.3		240	17.7	56	13.5
Married	1,689	81.5	438	78.4		1,074	79.3	327	79.0
Divorced/widowed	42	2.0	30	5.4		40	3.0	31	7.5
Employment status					0.131					0.001
Employed	1,454	70.2	370	66.2		857	63.3	219	52.9
Unemployed	428	20.7	137	24.5		171	12.6	64	15.5
Retired	190	9.2	52	9.3		326	24.1	131	31.6
Living alone	202	9.7	65	11.6	0.192	202	9.7	65	11.6	0.894
Personal income ≥6,000 yuan/month	338	16.3	75	13.4	0.095	435	32.1	103	24.9	0.005
No health insurance	1,529	73.8	438	78.4	0.028	651	48.1	207	50.0	0.494
Family history of psychiatric disorders	65	3.1	44	7.9	<0.001	65	4.8	43	10.4	<0.001
Current drinking	446	21.5	118	21.1	0.832	299	22.1	96	23.2	0.636
Current smoking	285	13.8	91	16.3	0.130	173	12.8	45	10.9	0.302
Taking sleeping pills	50	2.4	75	13.4	<0.001	37	2.7	95	22.9	<0.001
	Mean	SD	Mean	SD	P-value	Mean	SD	Mean	SD	P-value
Age (years)	39.8	15.1	42.4	15.4	0.001	42.9	16.6	47.2	16.6	0.004
Education (years)	9.5	3.9	8.6	4.0	0.001	12.0	4.2	10.9	4.1	<0.001
GAD-7 total score	2.7	3.7	5.6	5.4	<0.001a	2.4	3.5	4.8	5.3	<0.001a
PHQ-9 total score	3.0	3.6	6.8	5.6	<0.001a	2.6	3.3	6.1	5.4	<0.001a

Notes:

a Mann-Whitney U test; Values in bold are P<0.05 or P<0.001.

Abbreviations: GAD-7, Generalized Anxiety Disorder-7; PHQ-9, Patient Health Questionnaire-9.

Table 3 The regression analyses for factors associated with insomnia symptoms by region

Characteristics	Rural region with insomnia symptoms (n=559)				Urban region with insomnia symptoms (n=414)
	Wald χ^2	P-value	OR	95% CI	Wald χ^2	P-value	OR	95% CI
Females	–	–	–	–	2.498	0.114	1.254	0.95–1.66
Marital status
Unmarried			1.0				1.0
Married	1.156	0.282	0.839	0.61–1.16	1.154	0.283	1.268	0.82–1.96
Divorced/widowed	0.839	0.360	1.345	0.71–2.54	2.864	0.091	1.884	0.90–3.92
Employment status
Employed			–				1.0
Unemployed	–	–	–	–	0.185	0.667	0.913	0.60–1.38
Retired	–	–	–	–	1.046	0.306	0.782	0.49–1.25
Personal income ≥6,000 yuan/month	–	–	–	–	1.273	0.259	0.828	0.60–1.15
No health insurance	2.554	0.110	0.816	0.64–1.05	–	–	–	–
Family history of psychiatric disorders	1.787	0.181	1.385	0.86–2.23	1.769	0.183	1.420	0.85–2.38
Taking sleeping pills	37.938	<0.001	3.674	2.43–5.56	76.046	<0.001	6.890	4.47–10.63
Age (years)	12.994	<0.001	1.017	1.01–1.03	7.846	0.005	1.020	1.01–1.03
Education (years)	7.600	0.006	0.955	0.92–0.99	5.713	0.017	0.957	0.92–0.99
GAD-7 total score	0.661	0.416	1.014	0.98–1.05	2.048	0.152	0.968	0.93–1.01
PHQ-9 total score	103.295	<0.001	1.189	1.15–1.23	85.175	<0.001	1.250	1.19–1.31

Notes: As reported in the “Methods” section, in binary logistic regression analyses, insomnia symptoms in each region were dependent variable and the variables that significantly differed between with and without insomnia symptoms in univariate analyses were independent variables. Thus, “–” means not applicable.

Abbreviations: CI, confidence interval; GAD-7, generalized anxiety Disorder-7; OR, odds ratio; PhQ-9, Patient health Questionnaire-9.

Table S1 Prevalence of insomnia symptoms by age and region (or gender)

Age (years)	Insomnia symptoms			Age (years)	Insomnia symptoms
	Rural region % (95% CI)	Urban region % (95% CI)	Total % (95% CI)		Female % (95% CI)	Male % (95% CI)	Total % (95% CI)
<50 (n=3,119)	19.8 (18.0–21.5)	20.7 (18.4–23.1)	20.1 (18.7–21.5)	<50 (n=3,119)	20.8 (19.1–22.5)	18.7 (16.3–21.2)	20.1 (18.7–21.5)
≥50 (n=1,280)	25.6 (22.3–28.9)	28.4 (24.8–31.9)	27.0 (24.5–29.4)	≥50 (n=1,280)	30.1 (26.8–33.4)	22.6 (19.0–26.1)	27.0 (24.5–29.4)
Total (n=4,399)	21.2 (19.7–22.8)	23.4 (21.4–25.4)	22.1 (20.9–23.3)	Total (n=4,399)	23.2 (21.6–24.7)	20.1 (18.1–22.1)	22.1 (20.9–23.3)