Multimorbidity among inflammatory bowel disease patients in a tertiary care center: a retrospective study

Inflammatory bowel disease (IBD) is a chronic systemic inflammatory condition that debilitate the quality of life. Multimorbidity, a concept only beginning to emerge in IBD, is defined as two or more comorbidities present in the same individual. Notably, we used the term multimorbidity to refer to two or more comorbidities excluding IBD. Multimorbidity is linked to decreased quality of life, poorer disease outcomes, increased hospitalizations, healthcare costs and polypharmacy complications. We aim to estimate the prevalence of multimorbidity and to explore its effect on IBD patients.

We retrospectively reviewed all IBD patients registered in a validated web-based registry since February 2018. Data on patient demographics, comorbidities, IBD and extraintestinal complications were obtained. We analyzed the date using univariate, bivariate and multivariable analysis.

Among 767 IBD patients, 54.6% had Crohn's disease (CD), 41.9% had ulcerative colitis (UC) and 3.5% had IBD unclassified. The median age at diagnosis was 22 years (IQR: 15-29). Males compromised 50.2% of patients. According to the Montréal IBD classification, most UC patients had moderate UC (47.8%) while most CD patients had non-stricturing non-penetrating CD (49.8%). Overall, 10.3% IBD patients had multimorbidity and 23.9% had at least one comorbidity. The most common comorbidity was diabetes mellitus (4.9%) followed by essential hypertension (4%) and iron deficiency anemia (3%). Female gender (P = 0.008) and UC (P = 0.005) were more likely to have multimorbidity. Multimorbid IBD patients were more likely to develop thrombosis than non-multimorbid peers (16.7% vs. 1.6%; P < 0.001). Higher age at diagnosis (OR = 1.04, 95%CI: 1.01-1.07) and having a history of thrombosis (OR = 7.82, 95% CI: 2.67-22.92) are associated with increased risk of multimorbidity.

Multimorbidity is not uncommon among IBD patients, especially females diagnosed with UC. Our findings indicate that future studies are needed to explore the effects of multimorbidity on IBD patients.