Socioeconomic Inequality in Health Outcomes Among the Elderly: Evidence from a Cross-Sectional Study in China

Figures & data

Table 1 Description of Independent Variables

Variables	Description of Variables
Age
60–69^a
70–79	70–79 = 1, else = 0
≥ 80	80 and above = 1, else = 0
Gender
Female^a
Male	Female = 0, male = 1
Marital status
Divorced or else^a
Married	Divorced or else = 0, married = 1
Educational attainment
Primary school and below^a
Junior high school	Junior high school = 1,else = 0
Senior high school	Senior high school = 1, else = 0
Higher education	Higher education = 1, else = 0
Household income, RMB	Continuous variable
Health insurance
Without health insurance^a
Covered by health insurance	Covered by health insurance = 1, else = 0
Geographic location
Living in eastern region^a
Living in central region	Living in central region = 1, else = 0
Living in western region	Living in western region = 1, else = 0
Residency location
Living in rural area^a
Living in urban area	Living in urban area = 1, else = 0
Smoking
No^a	Never smoke
Yes	Smoke = 1, else = 0
Drinking
No^a	Drank no alcohol last year
Yes	Drank alcohol last year = 1, else = 0
Social interaction
No^a	Had no social interaction activities last month
Yes	Had social interaction activities last month = 1, else = 0

Note: ^aIndicates the reference group.

Table 2 Characteristics of the Study Population

Independent Variable	All (N = 5643)
Age
60–69, n (%)	3610 (63.97)
70–79, n (%)	1627 (28.83)
≥ 80, n (%)	406 (7.19)
Gender
Female, n (%)	2364 (41.89)
Male, n (%)	3279 (58.11)
Marital status
Divorced or else, n (%)	1252 (22.19)
Married, n (%)	4391 (77.81)
Educational Attainment
Primary school and below, n (%)	4641 (82.24)
Junior high school, n (%)	721 (12.78)
Senior high school, n (%)	133 (2.36)
Higher education, n (%)	148 (2.62)
Household income, RMB
Mean (SD)	14,201.93 (112,105.60)
Health Insurance
Without health insurance, n (%)	1113 (19.72)
Covered by health insurance, n (%)	4530 (80.28)
Geographic Location
Living in eastern region, n (%)	2373 (42.05)
Living in central region, n (%)	1370 (24.28)
Living in western region, n (%)	1900 (33.67)
Residency Location
Living in rural area, n (%)	3999 (70.87)
Living in urban area, n (%)	1644 (29.13)
Smoking
No, n (%)	3658 (64.82)
Yes, n (%)	1985 (35.18)
Drinking
No, n (%)	3698 (65.53)
Yes, n (%)	1945 (34.47)
Social Interaction
No, n (%)	2851 (50.52)
Yes, n (%)	2792 (49.48)

Note: SD represents the standard deviation.

Figure 1 Concentration curve of ADL score.

Figure 2 Concentration curve of CES-D score.

Table 3 Decomposition Analysis of Concentration Index in ADL Score

Variable	Elasticity	Ck	Absolute Contribution to C	Percentage Contribution to C
Age
60–69	Ref
70–79	0.0119	−0.0938	−0.0011	17.37
≥ 80	0.0065	−0.0717	−0.0005	7.19
Gender
Female	Ref
Male	−0.0088	0.0610	−0.0005	8.38
Marital status
Divorced or else	Ref
Married	0.0049	0.0108	0.0001	−0.81
Educational Attainment
Primary school and below	Ref
Junior high school	−0.0020	0.1455	−0.0003	4.41
Senior high school	−0.0006	0.1790	−0.0001	1.61
Higher education	−0.0001	0.1629	0.00001	0.23
Household income	−0.0202	0.1315	−0.0027	41.15
Health Insurance
Without health insurance	Ref
Covered by health insurance	−0.0132	0.0022	0.00003	0.46
Geographic Location
Living in eastern region	Ref
Living in central region	0.0036	0.0385	0.0001	−2.14
Living in western region	−0.0080	0.0011	0.000009	0.14
Residency Location
Living in rural area	Ref
Living in urban area	−0.0072	0.0514	−0.0004	5.78
Smoking
No	Ref
Yes	−0.0027	0.0226	−0.0001	0.93
Drinking
No	Ref
Yes	−0.0027	0.0530	−0.0001	2.22
Social Interaction
No	Ref
Yes	−0.0152	−0.0050	0.0001	−1.18

Notes: C_k indicates the concentration index of each explanatory variable; C stands for the concentration index of each independent variable; Ref represents the reference group.

Table 4 Decomposition Analysis of Concentration Index in CES-D Score

Variable	Elasticity	Ck	Absolute Contribution to C	Percentage Contribution to C
Age
60–69	Ref
70–79	−0.0094	−0.0938	0.0009	−5.61
≥ 80	−0.0072	−0.0717	0.0005	−3.26
Gender
Female	Ref
Male	−0.0454	0.0610	−0.0028	17.55
Marital Status
Divorced or else	Ref
Married	−0.0383	0.0108	−0.0004	2.61
Educational Attainment
Primary school and below	Ref
Junior high school	−0.0116	0.1455	−0.0017	10.67
Senior high school	−0.0018	0.1790	−0.0003	2.07
Higher education	−0.0019	0.1629	−0.0003	1.99
Household income	−0.0821	0.1315	−0.0108	68.41
Health Insurance
Without health insurance	Ref
Covered by health insurance	−0.0062	0.0022	0.00001	0.09
Geographic Location
Living in eastern region	Ref
Living in central region	0.0155	0.0385	0.0006	−3.78
Living in western region	0.0111	0.0011	0.00001	−0.08
Residency Location
Living in rural area	Ref
Living in urban area	−0.0199	0.0514	−0.0010	6.49
Smoking
No	Ref
Yes	−0.0009	0.0226	−0.00002	0.12
Drinking
No	Ref
Yes	−0.0080	0.0530	−0.0004	2.68
Social Interaction
No	Ref
Yes	−0.0276	−0.0050	0.0001	−0.87

Notes: C_k indicates the concentration index of each explanatory variable; C stands for the concentration index of each independent variable; Ref represents the reference group.