Table 1. Balancing check of covariates before and after propensity score matching based on logit model.

Variable	Unmatched or matched	Mean		%bias	t-test
		Treated	Control		t	P
Sex (male)	U	0.50394	0.43132	14.6	1.53	0.127
	M	0.50000	0.45161	9.7	0.76	0.448
Marriage (married)	U	0.99213	0.91784	36.4	3.02	0.003
	M	0.99194	0.99194	0.0	0.00	1.000
Age (yr)	U	61.74700	47.42200	112.5	10.60	0.000
	M	61.33000	61.84200	–4.0	–0.37	0.708
Height (cm)	U	163.36000	163.61000	–3.2	–0.34	0.734
	M	163.35000	162.87000	6.2	0.49	0.628
Weight (cm)	U	64.72400	62.17100	23.1	2.41	0.016
	M	64.63700	64.82300	–1.7	–0.13	0.895
Systolic pressure (mmHg)	U	128.32000	123.46000	30.2	3.23	0.001
	M	128.23000	129.10000	–5.4	–0.41	0.686
Diastolic pressure (mmHg)	U	77.96100	78.06300	–1.0	–0.11	0.916
	M	78.35500	79.33900	–9.8	–0.79	0.430
Hypertension	U	0.40945	0.15661	58.3	6.87	0.000
	M	0.41935	0.41935	0.0	0.00	1.000
Type 2 diabetes mellitus	U	0.03150	0.01155	13.7	1.75	0.080
	M	0.03226	0.02419	5.6	0.38	0.703
Dyslipidemia	U	0.00787	0.04878	–24.8	–2.11	0.035
	M	0.00806	0.00806	0.0	0.00	1.000
Coronary artery disease	U	0.00000	0.00000
	M	0.00000	0.00000
Other CVDs	U	0.11024	0.01669	39.0	5.85	0.000
	M	0.08871	0.06452	10.1	0.71	0.476
Pulmonary diseases	U	0.03937	0.01027	18.7	2.56	0.011
	M	0.04032	0.04032	0.0	0.00	1.000
The miscellaneous	U	0.10236	0.07445	9.8	1.08	0.278
	M	0.10484	0.10484	0.0	0.00	1.000

Dichotomous variables were taken as 1 for “yes”, otherwise as 0. U, unmatched; M, matched; CVD, cardiovascular disease.