TABLE 1

Incidence or prevalence ratios of Crohn's disease and ulcerative colitis in patients with chronic respiratory diseases

Authors [ref.]	Chronic respiratory diseases	Patients	Crohn's disease	Ulcerative colitis
*Ekbom et al. [32]*	COPD	180 239	HR 2.72 (95% CI 2.33–3.18)	1.83 (95% CI 1.61–2.09)
*Raj et al. [28]*	CAD	2192	OR 5.96 (95% CI 1.94–18.31)	4.21 (95% CI 1.71–10.41)
*Brassard et al. [34]*	Asthma	136 178	IRR 1.27 (95% CI 1.22–1.31)	0.99 (95% CI 0.94–1.04)
*Brassard et al. [34]*	COPD	143 904	IRR 1.55 (95% CI 1.49–1.62)	1.30 (95% CI 1.24–1.37)

Data are presented as n, unless otherwise stated. Bold type signifies statistically significant results. COPD: chronic obstructive pulmonary disease; HR: hazard ratio; CAD: chronic airway diseases; IRR: incidence rate ratio.