Table 1 Core characteristics of cases and controls
Clinical diagnosis | ACR 1990 criteria fulfilled | Biopsy-positive | ||||
|---|---|---|---|---|---|---|
Cases | Controls | Cases | Controls | Cases | Controls | |
N = 881 | N = 2577 | N = 792 | N = 2314 | N = 528 | N = 1584 | |
Age at onset1 | 73 (8.6) | 73 (8.6) | 73.1 (8.5) | 73.1 (8.5) | 73.5 (7.9) | 73.5 (7.9) |
Female2 | 626 (71.1) | 1823 (70.7) | 566 (71.5) | 1647 (71.2) | 378 (71.6) | 1134 (71.6) |
Urban2 | 538 (61.1) | 1360 (52.8) | 484 (61.1) | 1216 (52.5) | 329 (62.3) | 839 (53.0) |
Biopsy-positive2 | 537 (61.0) | – | 528 (66.7) | – | 528 (100) | – |
Median observation time3 | 8 [3, 14] | 7 [3, 12] | 8 [3, 14] | 7 [3, 11] | 6 [3, 13] | 9 [6, 13] |
Number of deaths during observation2 | 490 (55.6) | 1517 (58.9) | 432 (54.5) | 1335 (57.7) | 292 (55.3) | 952 (60.1) |
Age at death1 | 83.6 (7.5) | 84.7 (7.5) | 83.8 (7.4) | 84.6 (7.6) | 83.8 (6.9) | 84.7 (7.4) |
Time to death4 | 12 (11, 13) | 12 (11, 12) | 12 (11, 13) | 12 (11, 12) | 12 (11, 13) | 12 (11, 12) |