| N (%) or mean (standard deviation) | ||||
| All patients starting anti-TNF | Patients starting 1998–2001 | Patients starting 2002–6 | Patients developing lymphoma | |
| Overall | 6604 (100%) | 2492 (100%) | 4112 (100%) | 26 (100%) |
| Sex | ||||
| Men | 1630 (25%) | 627 (25%) | 1003 (24%) | 9 (35%) |
| Women | 4974 (75%) | 1865 (75%) | 3109 (76%) | 17 (65%) |
| Mean age at entry, years | 55 (13) | 55 (13) | 55 (13) | 63 (11) |
| Year of first anti-TNF start | , | |||
| 1998–2001 | 2492 | 2492 (100%) | 0 (0%) | 19 (71%) |
| 2002–3 | 1823 | 0 (0%) | 1823 (45%) | 5 (19%) |
| 2004–6 | 2289 | 0 (0%) | 2289 (55%) | 2 (7%) |
| RA duration at start, years | 10.6 (9.8) | 10.7 (9.5) | 10.5 (10) | 12 (10) |
| Swollen joints (28) at start | 9.5 (6.1) | 11 (6.2) | 8.7 (5.9) | 11 (7) |
| Tender joints (28) at start | 8.7 (6.7) | 9.7 (7.1) | 8.2 (6.5) | 10 (7.3) |
| DAS28 at start | 5.5 (1.3) | 5.8 (1.2) | 5.3 (1.4) | 5.7 (1.2) |
| HAQ at start | 1.4 (0.6) | 1.5 (0.6) | 1.3 (0.6) | 1.5 (1.2) |
| ESR at start | 37 (25) | 42 (26) | 34 (25) | 38 (25) |
| DMARD at start | ||||
| No | 1057 (16%) | 481 (19%) | 576 (14%) | 4 (15%) |
| Methotrexate | 4563 (69%) | 1612 (65%) | 2951 (72%) | 15 (58%) |
| Other than methotrexate | 697 (11%) | 266 (11%) | 431 (11%) | 5 (19%) |
| No information | 287 (4%) | 133 (5.3%) | 154 (3.7%) | 2 (7%) |
| Oral steroids | ||||
| Yes | 3383 (51%) | 1223 (49%) | 2160 (52%) | 10 (38%) |
| No | 2216 (33%) | 608 (24%) | 1608 (39%) | 8 (31%) |
| No information | 1005 (15%) | 661 (27%) | 344 (8.4%) | 8 (30%) |
| Co-morbidity at treatment start | ||||
| Any infection | 746 (11%) | 244 (9.8%) | 502 (12%) | 4 (15%) |
| Diabetes | 268 (4.1%) | 116 (4.7%) | 152 (3.7%) | 2 (8%) |
| Any cardiovascular disease | 478 (7.2%) | 173 (6.9%) | 305 (7.4%) | 1 (4%) |
| Any chronic obstructive pulmonary disease | 228 (3.5%) | 83 (3.3%) | 145 (3.5%) | 1 (4%) |
| Joint replacement surgery | 1852 (28%) | 855 (34%) | 997 (25%) | 10 (38%) |
| Use of inpatient care up until treatment start | ||||
| No of all hospital discharges Q1/Q2/Q3/Q4 (%)* | 25/25/25/25 | 22/23/25/28 | 30/27/21/20 | 12/23/34/30 |
| No of hospital RA discharges Q1/Q2/Q3/Q4 (%), mean | 25/25/25/25, 3.4 | 28/14/24/32, 4.6 | 49/16/17/17, 2.7 | 6/6/12/42, 5.1 |
| Mean no of days in hospital | 58 (93) | 72 (101) | 51 (87) | 99 (121) |
*Q denotes quartiles as defined by the distribution among all 6404 patients. DAS28, disease activity score based on 28 joints; DMARD, disease-modifying antirheumatic drug; ESR, erythrocyte sedimentation rate; HAQ, health assessment questionnaire; RA, rheumatoid arthritis; TNF, tumour necrosis factor.