1. Subgroups ‐ study characteristics.
| Study | Follow‐up (weeks) | n | Group 1 | Group 2 | Group 3 | Group 4 | Group 5 | Disease duration | Eligibility | Previously treated with |
| Bathon 2000 (ERA) | 52 | 632 | ET 10 mg | ET 25 mg | ‐ | ‐ | PBO | < 3 years | MTX‐naive | DMARDs |
| Combe 2006 | 104 | 254 | ‐ | ET 25 mg | ET 25 mg + SSZ | SSZ | ‐ | < 20 years | ‐ | SSZ |
| Emery 2008 (COMET) | 104 | 542 | ‐ | ‐ | ET 25 mg + MTX | MTX | ‐ | < 2 years | MTX‐naive | DMARDs (4 weeks prior enrolment) |
| Hu 2009 | 24 | 238 | ‐ | ET 25 mg | ‐ | MTX | ‐ | NS (mean 7.7 years) | ‐ | DMARDs |
| Kameda 2010 | 104 | 151 | ‐ | ET 25 mg | ET 25 mg + MTX | ‐ | ‐ | NS (but subgroups by < 10 and > 10 years) | ‐ | MTX |
| Klareskog 2004 (TEMPO) | 156 | 686 | ‐ | ET 25 mg | ET 25 mg + MTX | MTX | ‐ | < 20 years | no MTX 6 months prior enrolment | DMARDs |
| Marcora 2006 | 24 | 26 | ‐ | ET 25 mg | ‐ | MTX | ‐ | < 6 months | DMARDs‐naive | |
| Moreland 1999 | 26 | 234 | ET 10 mg | ET 25 mg | ‐ | ‐ | PBO | NS (mean 12 years) | ‐ | DMARDs |
| Weinblatt 1999 | 24 | 89 | ‐ | ‐ | ET 25 mg + MTX | MTX | ‐ | NS (mean 13 years) | ‐ | MTX |
DMARD: disease‐modifying anti‐rheumatic drug; ET: etanercept; MTX: methotrexate; NS: not stated; PBO: placebo; SSZ: sulphasalazine.