Table 2 Co-morbidity at the start of first tumour necrosis factor (TNF) antagonist treatment in (1) the Swedish ARTIS register cohort of 4167 patients with rheumatoid arthritis (RA) starting treatment with TNF antagonists 1999–2003; (2) in the subset thereof who had a pre-treatment hospitalisation with RA; and (iii) among sex-, age- and calendar period-matched bio-naïve RA controls (4 per RA patient in (2)) from the Swedish Inpatient Register RA cohort of patients hospitalised with RA

Inpatient morbidity at TNF antagonist start	(1) All anti-TNF 1998–2003	(2) Anti-TNF 1998–2003, also in Inpatient Register RA cohort	(3) Controls from RA Inpatient Register RA cohort, matched to (2)
Number of patients	4167 (100%)	2692 (100%)	10 295 (100%)
RA discharge	2692 (65%)	2692 (100%)	10 295 (100%)
Infection	1087 (26%)	855 (32%)	3078 (30%)
Cardiac disease	763 (18%)	604 (22%)	2620 (25%)
COPD	157 (3.8%)	124 (4.6%)	552 (5.4%)
Diabetes	175 (3.6%)	141 (5.2%)	530 (5.2%)
Knee replacement	306 (7.3%)	299 (11%)	929 (9.0%)
Hip replacement	668 (16%)	648 (24%)	1643 (16%)
Shoulder joint replacement	128 (3.1%)	126 (4.7%)	232 (2.3%)
Foot surgery	652 (16%)	631 (23%)	1493 (15%)
Total days in hospital (mean/median)	65/30	89/53	93/44
Number of discharges, all diagnoses	8.2/5	11/8	9.8/7

CODD, chronic obstructive pulmonary disease.