psoriasis aimed to study the incidence of these diseases over 2 years). Methods: Patients aged 18 years-old with known or newly diagnosed SpA, IBD or psoriasis were recruited from rheumatology, IBD and dermatology offices from 15 hospitals. Clinical data were collected through direct interview and patient’s clinical record review. Results: The SpA cohort (mean age 48 years, men: 63%) comprised 601 patients with the following diagnoses: ankylosing spondylitis (55.1%), psoriatic arthritis (25.1%), undifferentiated SpA (16.1%), enteropathic arthritis (2.5%), others (1.3%). The prevalence of IBD (table) was 5.1% (95%CI: 3.7 7.2), and the specific diagnoses were Crohn’s disease (3.0%, 95%CI: 1.9 4.7), ulcerative colitis (1.0%, 95%CI: 0.5 2.2), and undifferentiated colitis (1.2%, 95%CI 0.6 2.4). The prevalence of IBD was 100% in those with enteropathic arthritis and upon removal of these patients, the prevalence of IBD in other SpA patients was 2.7% (95%CI: 1.7 4.4), with figures of 3.9%, 0.7% and 2.4% in patients with ankylosing spondylitis, psoriatic arthritis or undifferentiated SpA, respectively. The prevalence was similar in men and women (5.0% and 5.4%, p =NS), and in those with or without other extra-articular manifestations of SpA (4.9% and 6.7%, p =NS). It was slightly higher in those with SpA of longer duration (3.5%, 4.4% and 6.9% respectively for those with SpA of 8 years duration, P=NS), and in those without family history of SpA (6.4% versus 1.7%, p = 0.048). The multivariate analysis identified the absence of family history of SpA as the only variable associated to the presence of IBD (3.9 [95%CI: 1.1 16.7]). The psoriasis cohort comprised 528 patients, and only 7 had IBD (prevalence 1.3%, 95%CI: 0.6 2.7).