Baseline characteristics of the cohorts
| RTX (n=43) | All TNFi (n=309) | p Value | |
| Age (years) | 64.7 (11.4) | 62.5 (10.4) | 0.2 |
| Female, n (%) | 19 (44.2) | 179 (57.9) | 0.09 |
| Smoking history, n (%) | |||
| Current | 7 (16.3) | 64 (20.7) | 0.6 |
| Former | 27 (62.8) | 169 (54.7) | |
| Never | 9 (20.9) | 75 (24.6) | |
| Ethnicity | |||
| White | 37 (86.0) | 271 (87.7) | 0.97 |
| Other | 1 (2.4) | 7 (2.3) | |
| Missing, n (%) | 5 (11.6) | 31 (10.3) | |
| DAS28 | 6.3 (1.1) | 6.6 (1.0) | 0.03 |
| Missing, n (%) | 0 (0) | 2 (0.6) | |
| HAQ | 1.6 (0.7) | 2.1 (0.54) | <0.001 |
| Missing, n (%) | 6 (13.9) | 20 (6.4) | |
| Disease duration (years), median (IQR)* | 5 (3–13) | 12 (7–20) | <0.001 |
| Missing, n (%) | 0 (0) | 1 (0.3) | |
| Baseline steroid use, n (%) | 27 (62.8) | 177 (57.3) | 0.5 |
| Number of prior csDMARDs | 3.2 (1.2) | 4.0 (1.6) | <0.01 |
| Comorbidity, n (%)† | |||
| None | 10 (23.3) | 103 (33.3) | 0.3 |
| 1 comorbidity | 14 (32.6) | 113 (36.7) | |
| 2 comorbidity | 13 (30.2) | 64 (20.7) | |
| ≥3 comorbidity | 6 (13.9) | 29 (9.4) | |
| Hypertension | 18 (42.9) | 123 (39.9) | 0.7 |
| Ischaemic heart disease (angina + MI) | 9 (20.9) | 39 (12.6) | 0.1 |
| Stroke | 5 (11.9) | 16 (4.9) | 0.09 |
| Renal | 2 (4.6) | 11 (3.6) | 0.7 |
| Diabetes | 4 (9.3) | 17 (5.6 | 0.3 |
| Liver disease | 1 (2.3) | 12 (3.9) | 0.7 |
| Depression | 8 (18.6) | 49 (16.4) | 0.6 |
| Lung (asthma + COPD) | 18 (41.9) | 80 (25.6) | 0.03 |
| Asthma | 5 (11.9) | 32 (10.4) | 0.8 |
| Missing, n (%) | 1 (2.3) | 6 (1.9) | |
| COPD | 14 (33.3) | 58 (18.8) | 0.03 |
| Missing, n (%) | 1 (2.3) | 7 (2.3) | |
| Year of registration‡ | |||
| <2008 | 0 (0) | 309 (100) | NA |
| ≥2008 | 43 (100) | 0 (0) | |
Values are mean (SD), unless otherwise stated; categorical variables compared using Pearson chi-squared tests and continuous variables compared using Student’s t-tests; information about missing data only reported for variables in which missingness occurred.
*Comparison conducted using Wilcoxon rank-sum test.
†Hypertension, coronary heart disease (MI or angina), stroke, lung (asthma or bronchitis/emphysema), diabetes mellitus, depression, renal disease and liver disease.
‡Due to differences in recruitment periods for cohorts, between group comparisons are not appropriate for year of registration.
COPD, chronic obstructive pulmonary disease; csDMARDs, conventional synthetic disease modifying antirheumatic drug; DAS28, disease activity score-28; HAQ, Health Assessment Questionnaire; MI, myocardial infarction; pyrs, person years; NA, not applicable; RTX, rituximab; TNFi, tumour necrosis factor inhibitor.