Table 1.
Baseline characteristics of patients
| First anti-TNF drug | |||||
|---|---|---|---|---|---|
| nbDMARD n=3629 | All anti-TNF n=11 881 | Etanercept n=4139 | infliximab n=3475 | Adalimumab n=4267 | |
| Mean age, years (SD) | 60 (12) | 56 (12) | 56 (12) | 56 (12) | 57 (12) |
| Women, % | 2621 (72) | 9053 (76) | 3193 (77) | 2626 (76) | 3234 (76) |
| Country of residence (%) | |||||
| England | 3066 (84) | 10 064 (85) | 3572 (86) | 3039 (87) | 3453 (81) |
| Northern Ireland | 365 (10) | 299 (3) | 45 (1) | 56 (2) | 198 (5) |
| Scotland | 156 (4) | 920 (8) | 287 (7) | 188 (5) | 445 (10) |
| Wales | 42 (1) | 598 (5) | 235 (6) | 192 (6) | 171 (4) |
| Smoking history, n (%) | |||||
| Current smoker | 857 (24) | 2580 (22) | 846 (20) | 757 (22) | 977 (23) |
| Former smoker | 1437 (40) | 4510 (38) | 1576 (38) | 1314 (38) | 1620 (38) |
| Never smoked | 1317 (36) | 4714 (40) | 1691 (41) | 1386 (40) | 1637 (38) |
| Not recorded | 18 (0) | 77 (1) | 26 (1) | 18 (1) | 33 (1) |
| Ethnicity, n (%): | |||||
| White | 2780 (77) | 9829 (83) | 3434 (83) | 2814 (81) | 3581 (84) |
| Other | 70 (2) | 404 (3) | 141 (3) | 126 (4) | 137 (3) |
| Not recorded | 779 (21) | 1648 (14) | 564 (14) | 535 (15) | 549 (13) |
| Skin cancer before registration, n (%) | 106 (2.9) | 177 (1.5) | 68 (1.6) | 40 (1.2) | 69 (1.6) |
| Mean DAS28 (SD) | 5.1 (1.3) | 6.6 (1.0) | 6.6 (1.0) | 6.6 (1.0) | 6.5 (1.0) |
| Mean HAQ (SD) | 1.5 (0.8) | 2.0 (0.6) | 2.1 (0.6) | 2.1 (0.5) | 1.9 (0.6) |
| Median disease duration, years (IQR) | 6 (1, 15) | 11 (6, 19) | 12 (6, 19) | 12 (6, 19) | 10 (5, 18) |
| Baseline steroid use, n (%) | 831 (23) | 5252 (44) | 1979 (48) | 1609 (46) | 1664 (39) |
| Baseline NSAID use, n (%) | 1964 (54) | 6976 (59) | 2439 (58) | 2513 (59) | 2513 (59) |
| Number of previous DMARD, median (IQR) | 2 (1, 3) | 4 (3, 5) | 4 (3, 5) | 4 (3, 5) | 3 (3, 5) |
| Ever exposed to azathioprine, n (%) | 259 (7) | 2474 (21) | 1059 (26) | 719 (21) | 696 (16) |
| Ever exposed to ciclosporin, n (%) | 150 (4) | 1943 (16) | 792 (19) | 704 (20) | 447 (10) |
| Entry year | |||||
| pre-2003 | 8 (0) | 1415 (12) | 205 (5) | 1180 (34) | 30 (1) |
| 2003 | 309 (9) | 311 (26) | 1531 (37) | 1106 (32) | 479 (11) |
| 2004 | 891 (25) | 3279 (28) | 1978 (48) | 506 (15) | 795 (19) |
| 2005 | 925 (25) | 1618 (14) | 422 (10) | 343 (10) | 853 (20) |
| 2006 | 751 (21) | 1137 (10) | 2 (0) | 275 (8) | 860 (20) |
| 2007 | 337 (9) | 842 (7) | 1 (0) | 65 (2) | 776 (18) |
| 2008 | 408 (11) | 474 (4) | 0 (0) | 0 (0) | 474 (11) |
DAS28, disease activity score in 28 joints; HAQ, health assessment questionnaire; nbDMARD, non-biological disease-modifying antirheumatic drug; NSAID, non-steroidal anti-inflammatory drug; TNF, tumour necrosis factor.