Table 3. Risk factors of PTSD symptoms by logistic regression.

	PTSD No.(%)	Bivariate OR (95% CI)	P Value	Multivariate OR(95% CI)	P Value
Gender			0.002	–
male	37(3.1)	0.53(0.36–0.80)
female	76(5.7)	1.00
Age (years)			0.935	–
<60 yrs	84(4.5)	0.98(0.64–1.51)
≥60 yrs	29(4.5)	1.00
Education			0.028	–
Primary school or lower	74(5.3)	1.56(1.05–2.32)
Higher than primary school	39(3.5)	1.00
Ethnicity			0.285		0.015
Han	106(4.6)	1.53(0.70–3.32)		2.70(1.21–6.02)
Minorities	7(3.1)	1.00		1.00
Household income			0.001	–
RMB0–5000	20(6.7)	2.80(1.51–5.17)
RMB5000–20000	70(5.3)	2.19(1.36–3.54)
RMB≥20000	23(2.5)	1.00
Chronic diseases*			0.001	–
Yes	51(6.7)	1.96(1.34–2.86)
No	62(3.5)	1.00
Two-week prevalence rate			<0.001		<0.001
Yes	46(9.8)	3.24(2.19–4.78)		2.45(1.62–3.72)
No	67(3.3)	1.00		1.00
Displaced after earthquake			<0.001		0.024
Yes	36(11.3)	3.52(2.32–5.33)		1.69(1.07–2.66)
No	77(3.5)	1.00		1.00
Have regular income after earthquake			0.003		0.001
Yes	23(2.7)	0.49(0.31–0.78)		0.45(0.27–0.73)
No	90(5.4)	1.00		1.00
Received mental health support after earthquake			<0.001		0.018
Yes	37(13.9)	4.74(3.12–7.19)		1.77(1.10–2.85)
No	74(3.3)	1.00		1.00
Family member died or missing during earthquake			<0.001		0.001
Yes	58(11.0)	4.34(2.96–6.37)		2.14(1.37–3.35)
No	55(2.8)	1.00		1.00
Injured due to the disaster			<0.001		0.006
Yes	59(10.5)	4.16(2.83–6.09)		1.86(1.19–2.90)
No	54(2.8)	1.00		1.00
Lost home or property			<0.001
Yes	111(5.3)	12.49(3.07–50.74)		–
No	2(0.4)	1.00
Witnessed someone being killed or injured			<0.001		0.013
Yes	83(8.6)	4.77(3.12–7.30)		1.96(1.15–3.35)
No	30(1.9)	1.00		1.00

^*PTSD symptoms: PCL-C score of 17 items ≥38.

Abbreviations: CI, confidence interval; OR, odds ratio; PTSD, posttraumatic stress disorder.

–Variable was not retained in backward stepwise regression procedure.