Table 2 Sample characteristics before and after PSM for WeChat users and non-WeChat users
Variable | Before PSM (N = 15,428) | After PSM (N = 4545) | ||||
|---|---|---|---|---|---|---|
WeChat user (N = 2179) | Non-WeChat user (N = 13,249) | P value | WeChat user (N = 1906) | Non-WeChat user (N = 2639) | P value | |
Depressive symptom |  |  | < 0.001 |  |  | < 0.001 |
 CES-D < 10 | 1680 (77.1) | 8077 (61.0) |  | 1455 (76.3) | 1814 (68.7) |  |
 CES-D > =10 | 499 (22.9) | 5172 (39.0) |  | 451 (23.7) | 825 (31.3) |  |
 Levels of depression | 6.3 ± 0.1 | 8.8 ± 0.1 | < 0.001 | 6.4 ± 0.1 | 7.5 ± 0.1 | < 0.001 |
 Age | 55.3 ± 7.2 | 61.8 ± 9.3 | < 0.001 | 55.7 ± 7.4 | 56.2 ± 7.3 | 0.033 |
Gender |  |  | < 0.001 |  |  | 0.558 |
 Female | 985 (45.2) | 6887 (52.0) |  | 868 (45.5) | 1225 (46.4) |  |
 Male | 1194 (54.8) | 6362 (48.0) |  | 1038 (54.5) | 1414 (53.6) |  |
Marital status |  |  | < 0.001 |  |  | 0.444 |
 Unmarried | 158 (7.3) | 1754 (13.2) |  | 139 (7.3) | 177 (6.7) |  |
 Married | 2021 (92.7) | 11,495 (86.8) |  | 1767 (92.7) | 2462 (93.3) |  |
Residence |  |  | < 0.001 |  |  | < 0.001 |
 Rural | 937 (43.0) | 9965 (75.2) |  | 906 (47.5) | 1450 (54.9) |  |
 Urban | 1242 (57.0) | 3284 (24.8) |  | 1000 (52.5) | 1189 (45.1) |  |
Education |  |  | < 0.001 |  |  | < 0.001 |
 No formal education | 33 (1.5) | 2772 (20.9) |  | 33 (1.7) | 72 (2.7) |  |
 Elementary school | 506 (23.2) | 6277 (47.4) |  | 499 (26.2) | 847 (32.1) |  |
 Middle school | 775 (35.6) | 2926 (22.1) |  | 736 (38.6) | 997 (37.8) |  |
 High school | 657 (30.2) | 1138 (8.6) |  | 516 (27.1) | 623 (23.6) |  |
College or above | 208 (9.5) | 136 (1.0) | Â | 122 (6.4) | 100 (3.8) | Â |
Sleep time | 1.8 ± 0.3 | 1.8 ± 0.4 | < 0.001 | 1.8 ± 0.3 | 1.8 ± 0.3 | 0.678 |
Self-reported health |  |  | < 0.001 |  |  | 0.049 |
 Very poor | 53 (2.4) | 813 (5.8) |  | 51 (2.7) | 91 (3.4) |  |
 Poor | 206 (9.5) | 2688 (20.3) |  | 200 (10.5) | 328 (12.4) |  |
 Fair | 1103 (50.6) | 6580 (49.7) |  | 986 (51.7) | 1347 (51.0) |  |
 Good | 446 (20.5) | 1564 (11.8) |  | 357 (18.7) | 431 (16.3) |  |
 Very good | 371 (17.0) | 1604 (12.1) |  | 312 (16.4) | 442 (16.7) |  |
ADL |  |  | < 0.001 |  |  | 0.844 |
 No impaired | 2143 (98.3) | 12,395 (93.6) |  | 1870 (98.1) | 2587 (98.0) |  |
 Impaired | 36 (1.7) | 854 (6.4) |  | 36 (1.9) | 52 (2.0) |  |
Smoke status | Â | Â | 0.235 | Â | Â | 0.501 |
 Still have | 643 (29.5) | 3676 (27.7) |  | 563 (29.5) | 792 (30.0) |  |
 Quit | 309 (14.2) | 1917 (14.5) |  | 273 (14.3) | 346 (13.1) |  |
 No | 1227 (56.3) | 7656 (57.8) |  | 1070 (56.1) | 1501 (56.9) |  |
Drink status |  |  | < 0.001 |  |  | 0.042 |
 No | 1043 (47.9) | 8845 (66.8) |  | 966 (50.7) | 1418 (53.7) |  |
 Yes | 1136 (52.1) | 4404 (33.2) |  | 940 (49.3) | 1221 (46.3) |  |
Employment |  |  | < 0.001 |  |  | 0.418 |
 No | 629 (28.9) | 4431 (33.4) |  | 570 (29.9) | 760 (28.8) |  |
 Yes | 1550 (71.1) | 8818 (66.6) |  | 1336 (70.1) | 1879 (71.2) |  |
Pension insurance |  |  | < 0.001 |  |  | 0.602 |
 No | 164 (7.5) | 1397 (10.5) |  | 150 (7.9) | 219 (8.3) |  |
 Yes | 2015 (92.5) | 11,852 (89.5) |  | 1756 (92.1) | 2420 (91.7) |  |
Medical insurance | Â | Â | 0.033 | Â | Â | 0.739 |
 No | 41 (1.9) | 352 (2.6) |  | 41 (2.2) | 53 (2.0) |  |
 Yes | 2138 (98.1) | 12,897 (97.3) |  | 1865 (97.8) | 2586 (98.0) |  |
Chronic diseases |  |  | < 0.001 |  |  | 0.348 |
 No | 597 (27.4) | 2645 (20.0) |  | 499 (26.2) | 702 (26.6) |  |
 One | 566 (26.0) | 3131 (23.6) |  | 492 (25.8) | 664 (25.2) |  |
 Two | 405 (18.6) | 2722 (20.5) |  | 357 (18.7) | 516 (19.6) |  |
 Three | 292 (13.4) | 1889 (14.3) |  | 261 (13.7) | 314 (11.9) |  |
 Four and more | 319 (14.6) | 2862 (21.6) |  | 297 (15.6) | 443 (16.8) |  |