Table 2. Comparisons of baseline characteristics between the case and control group.

	Case group (n=540)	Control group (n=540)	P value
Age (years, mean ± SD)	71.6 ± 10.9	72.1 ± 9.8	0.428
Sex [n (%)]
Male	285 (52.8%)	291 (53.9%)	0.714
Female	255 (47.2%)	249 (46.1%)
BMI (kg/m2, mean ± SD)	22.4 ± 1.8	22.6 ± 1.8	0.068
Smoking status
Yes	241 (44.6%)	250 (46.3%)	0.582
No	299 (55.4%)	290 (53.7%)
Alcohol drinking
Yes	245 (45.4%)	254 (47.0%)	0.583
No	295 (54.6%)	286 (53.0%)
Fracture site
Lumbar	95 (17.6%)
Thighbone	165 (30.6%)
Proximal humerus	123 (22.8%)
Distal radius	115 (21.3%)
Thoracic vertebra	42 (7.8%)