Table 4.

Covariates balancing property test before and after matching (Treatment variable is social participation)

Variable	Unadjusted			Adjusted for the GPS
	[1, 9]	(9, 14]	(14, 30]	[1, 9]	(9, 14]	(14, 30]
	MD (SE)	MD (SE)	MD (SE)	MD (SE)	MD (SE)	MD (SE)
Gender	0.13 (0.29)	0.03 (0.17)	0.23 (0.35)	−0.00 (0.04)	0.01 (0.03)	−0.00 (0.04)
Age group
70–79 age group	−0.24 (0.28)	0.06 (0.17)	0.37 (0.34)	0.00 (0.04)	0.01 (0.04)	−0.11 (0.04)
80 age above	0.31 (0.29)	0.33 (0.19)	0.38 (0.60)	0.02 (0.02)	0.00 (0.03)	0.09*** (0.04)
Education
Primary school	−0.35 (0.29)	0.06 (0.18)	−0.18 (0.34)	−0.03 (0.04)	0.01 (0.03)	−0.05 (0.04)
Junior high school or above	−0.29 (0.39)	0.02 (0.21)	0.30 (0.38)	0.03 (0.03)	0.00 (0.03)	−0.04 (0.03)
Personal income	−2.40*** (0.14)	2.98*** (0.09)	8.41*** (0.18)	0.02 (0.07)	−0.01 (0.08)	−0.11 (0.07)
Work or not	−0.39 (0.29)	−0.27 (0.17)	0.01 (0.35)	0.04 (0.03)	−0.09** (0.03)	−0.03 (0.04)
Household registration type	0.89*** (0.34)	0.12 (0.19)	−0.54 (0.36)	−0.05 (0.03)	0.03 (0.03)	0.05 (0.04)
The number of children	4.93 *** (0.15)	10.33 *** (0.11)	16.25*** (0.18)	0.15 (0.09)	−0.21*** (0.08)	0.14 (0.11)
The number of friends	4.81*** (0.16)	9.51*** (0.16)	14.54*** (0.27)	0.63*** (0.22)	−0.22 (0.19)	−0.99 (0.23)
Chronic diseases	4.19*** (0.15)	10.00*** (0.11)	15.82*** (0.18)	−0.11 (0.08)	0.06 (0.08)	0.07 (0.09)
Life satisfaction	2.83*** (0.15)	8.23*** (0.10)	13.71 *** (0.17)	0.04 (0.06)	−0.02 (0.06)	−0.12 (0.08)
Duration of widowhood	−9.33*** (0.75)	−0.26 (0.64)	6.93*** (0.63)	−0.62 (0.77)	1.31 (0.81)	0.59 (0.97)
Smoke	−0.04 (0.39)	−0.17 (0.249)	−0.68 (0.55)	−0.02 (0.02)	−0.01 (0.02)	0.02 (0.03)
Drink	−1.04 * (0.56)	−0.89 *** (0.31)	−0.55 (0.60)	−0.01 (0.02)	−0.01 (0.01)	0.01 (0.02)

Mean Difference (MD) (Standard error, SE, in parenthesis)

*p < 0.01; **p < 0.05; ***p < 0.01