Table 2.

Lower GI perforations, crude and IPTW-adjusted incidence rates and contrasts between non-TNFi and TNFi bDMARDs

Cohort	Crude IR (95% CI)	Crude HR (95% CI)	HR p value	IPTW adj. IR (95% CI)	IPTW adj. HR (95% CI)	HR p value
TNFi	1.57 (1.21–2.05)	Ref	‒	1.85 (1.34–2.36)	Ref	‒
Abatacept	2.62 (1.52–4.52)	1.68 (0.93–3.03)	0.0877	1.98 (0.73–3.23)	1.07 (0.55–2.10)	0.8341
Rituximab	2.11 (1.39–3.21)	1.36 (0.82–2.24)	0.2338	1.65 (0.84–2.46)	0.89 (0.50–1.58)	0.6980
Tocilizumab	4.10 (2.70–6.22)	2.61 (1.61–4.24)	0.0001	4.07 (2.14–6.00)	2.20 (1.28–3.79)	0.0045

IPTW adjustment for demographic characteristics (age, sex, education level), year of treatment start, disease history (GI perforations, diverticular disease, intestinal vascular disease, inflammatory bowel disease, other GI disorders, diabetes, chronic obstructive pulmonary disease, hospitalised infections, cardiovascular disease, cancer, joint surgery, number of hospitalisations), RA parameters (RA duration, rheumatoid factor, erythrocyte sedimentation rate CRP, DAS28CRP score), Health Assessment Questionnaire score, comedication with methotrexate, other conventional disease-modifying antirheumatic drugs, selective COX2 inhibitors, non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticoids and cumulated use of glucocorticoids and of NSAIDs.

bDMARD, biological disease-modifying antirheumatic drugs; COX, cyclooxygenase; CRP, C reactive protein; GI, gastrointestinal; IPTW, inverse probability treatment weighting; IR, incidence rate; RA, rheumatoid arthritis; TNFi, tumour necrosis factor inhibitors.