Table 7

Multivariable negative binomial regression model for hospital admission (n=1000)

	Univariable analyses			Multivariable analysis
	IRR	95% CI	P value	aIRR	95% CI	P value
Anti-TNF-α monotherapy	1.67	0.92 to 3.06	0.10	1.66	0.91 to 3.04	0.10
Thiopurine monotherapy	1.40	0.88 to 2.22	0.15	1.35	0.85 to 2.15	0.20
Anti-TNF-α and thiopurine	1.63	0.71 to 3.78	0.25	1.65	0.71 to 3.82	0.24
Systemic corticosteroids	1.55	0.97 to 2.50	0.07	1.52	0.94 to 2.44	0.09
Smoking during pregnancy	1.52	0.70 to 3.32	0.29
Disease activity	1.27	0.81 to 1.98	0.30
Obstetric complications	0.92	0.49 to 1.74	0.80
Preterm birth	1.17	0.66 to 2.05	0.60
Day care attendance	1.14	0.60 to 2.15	0.69
Breast feeding (>1 month)	0.95	0.64 to 1.40	0.79

aIRR, adjusted incidence rate ratio; IRR, incidence rate ratio ; TNF, tumour necrosis factor.