Table 2.

The results of univariate and multivariate Cox proportional hazard models

Factors	Classification	Nonfracture group (n = 15,377)	Fracture group (n = 2,097)	Crude HR (95% CI)	P value	Adjusted HR (95% CI) a (n = 10,032)	P value
Age	Continuous			1.04 (1.04–1.05)	< 0.001	1.04 (1.03–1.05)	< 0.001
Sex	Men	7,550	786	Ref		Ref
	Women	7,827	1,311	1.59 (1.45–1.73)	< 0.001	1.85 (1.55–2.20)	< 0.001
PTSD symptoms	No	10,451	1,237	Ref		Ref
	Yes	3,423	586	1.43 (1.30–1.58)	< 0.001	1.26 (1.10–1.44)	0.001
Experience of earthquake	No	1,072	166	Ref		Ref
	Yes	14,305	1,931	0.82 (0.70–0.97)	0.017	0.92 (0.69–1.20)	0.531
History of mental illness	No	14,170	1,896	Ref		Ref
	Yes	741	134	1.45 (1.21–1.72)	< 0.001	0.98 (0.76–1.27)	0.869
Need for assistance	No	13,745	1,796	Ref		Ref
	Yes	1,249	240	1.85 (1.62–2.12)	< 0.001	1.14 (0.92–1.41)	0.240
History of cancer	No	13,745	1,796	Ref		Ref
	Yes	1,249	240	1.31 (1.13–1.51)	< 0.001	1.49 (1.24–1.79)	< 0.001
History of stroke	No	13,287	1,768	Ref		Ref
	Yes	1,434	254	1.41 (1.24–1.61)	< 0.001	1.25 (1.03–1.52)	0.023
History of heart disease	No	12,068	1,545	Ref		Ref
	Yes	2,712	473	1.37 (1.23–1.51)	< 0.001	1.30 (1.13–1.50)	< 0.001
History of diabetes mellitus	No	9,695	1,274	Ref		Ref
	Yes	4,942	734	1.14 (1.04–1.25)	0.004	1.23 (1.09–1.39)	< 0.001
Smoking habit	Never smoked	8,866	1,321	Ref		Ref	(trend p = 0.057)
	Former smoker	4,317	465	0.73 (0.66–0.81)	< 0.001	1.03 (0.86–1.24)	0.739
	Current smoker	1,468	176	0.83 (0.71–0.97)	0.022	1.29 (1.02–1.63)	0.036
Drinking habit	Never drinks or rarely drinks (less than once a month)	8,121	1,186	Ref		Ref	(trend p = 0.134)
	Former drinker	847	111	0.95 (0.78–1.15)	0.595	1.22 (0.92–1.63)	0.171
	Current drinker (more than once a month)	5,893	703	0.79 (0.72–0.87)	< 0.001	1.13 (0.98–1.31)	0.105
Level of sleep satisfaction	Satisfied with sleep	4,738	571	Ref		Ref	(trend p = 0.142)
	Slightly unsatisfied with sleep	4,488	634	1.15 (1.02–1.28)	0.018	1.04 (0.92–1.19)	0.552
	Quite unsatisfied with sleep	1,408	242	1.40 (1.20–1.62)	< 0.001	1.03 (0.85–1.24)	0.796
	Very dissatisfied with sleep or does not sleep at all	483	100	1.69 (1.37–2.09)	< 0.001	1.33 (1.02–1.74)	0.035
Exercise habit	Almost daily	3,829	474	Ref		Ref	(trend p = 0.359)
	2 to 4 times a week	4,620	611	1.06 (0.94–1.20)	0.338	1.00 (0.85–1.17)	0.976
	Approximately once a week	2,193	312	1.16 (1.00–1.33)	0.047	1.08 (0.89–1.30)	0.443
	Almost never	4,000	586	1.24 (1.10–1.40)	< 0.001	1.06 (0.90–1.25)	0.480

^aAdjusted for age, sex, PCL score, experience of earthquake, history of mental illness, need for assistance, history of cancer, history of stroke, history of heart disease, history of diabetes mellitus, smoking habit, drinking habit, level of sleep satisfaction, and exercise habit. 95% CI 95% confidence interval, HR hazard ratio, Ref reference, PTSD post–traumatic stress disorder. Cox proportional hazard model; p < 0.05 was considered statistically significant