Table 2 Association of SEP (FAI, education, occupation) and conventional potential confounding factors among urban and rural participants in Nanjing, China
Characteristic | Education in years (n and %*) | P ** | Family average income (n and %*) | P ** | Occupation (n and %*) | P ** | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Lower | Middle | Higher | Lower | Middle | Higher | Blue collar | White collar | ||||
Area | |||||||||||
 Urban | 1962 (25.6) | 1846 (30.0) | 2433 (44.4) | < 0.001 | 1319 (19.5) | 2009 (33.1) | 2913 (47.4) | < 0.001 | 5146 (81.5) | 1095 (18.5) | < 0.001 |
 Rural | 1968 (76.5) | 352 (16.2) | 137 (7.3) |  | 1724 (68.6) | 545 (23.6) | 188 (7.8) |  | 2280 (92.4) | 177 (7.6) |  |
Gender | |||||||||||
 Male | 1809 (27.3) | 1121 (28.6) | 1325 (44.2) | < 0.001 | 1479 (23.6) | 1221 (31.4) | 1555 (45.0) | 0.071 | 3613 (82.2) | 642 (17.8) | 0.584 |
 Female | 2121 (33.9) | 1077 (28.8) | 1245 (37.4) |  | 1585 (24.3) | 1328 (32.2) | 1530 (43.6) |  | 3813 (82.8) | 630 (17.2) |  |
Age (years) | |||||||||||
 25–39 | 413 (11.4) | 601 (23.52.2) | 1540 (66.5) | < 0.001 | 616 (18.7) | 716 (31.8) | 1222 (49.5) | < 0.00 | 2029 (78.1) | 525 (21.9) | < 0.001 |
 40–54 | 1648 (37.3) | 860 (31.2) | 747 (31.5) |  | 1241 (27.2) | 931 (31.2) | 1083 (41.6) |  | 2816 (84.4) | 439 (15.6) |  |
 55–69 | 1869 (51.3) | 737 (35.5) | 283 (13.3) |  | 1205 (28.6) | 903 (34.7) | 781 (36.8) |  | 2581 (86.7) | 308 (13.3) |  |