Factors associated with comorbidity in hospitalized and non-hospitalized inflammatory bowel disease patients: A single-center, preliminary study.

Background: Inflammatory bowel disease (IBD) may be burdened by other comorbid conditions. We herein sought to assess comorbidity in hospitalized and non-hospitalized IBD patients.

Methods: This was part of the San MAtteo Complexity (SMAC) study (2017-2019). Data of hospitalized IBD patients were compared to gender- and age-matched IBD outpatients in a 2:1 fashion. The association of comorbidity in relation to hospitalization and clinical and socioeconomic factors was assessed.

Results: We included 104 patients, 27 hospitalized (median age 49 years, IQR 32-70) and 77 outpatients (median age 54 years, IQR 37-68). Comorbidity was reported in 63/104 patients (60.6%), of whom 45 (58.5%) non-hospitalized and 18 (66.6%) hospitalized. Patients with comorbidity were older (median 60 years, IQR 44-61 vs median 40 years, IQR 28-50 vs; p<0.001), had a higher Cumulative Illness Rating Scale severity index (median 1.85, IQR 1.5-2.5 vs median 1.31, IQR 1.2-2.5; p=0.002), were more commonly female (37, 60.7% vs 14, 35.0%; p=0.01), frailer (14, 22.2% vs 1, 2.4%; p=0.004), and had a lower educational level (13, 20.6% vs 2, 4.9%; p=0.04). In a bivariable analysis, factors associated to comorbidity were age >65 years (OR 5.30, 95% CI 1.81-15.55; p=0.002), female sex (OR 2.92, 95% CI 1-27-6.71; p=0.012), income <1000€ (OR 3.04, 95% CI 1.09-8.44; p=0.033), schooling <8 years (OR 5.09, 95% CI 1.08-23.96; p=0.039), frailty (OR 12.56, 95% CI 1.48-106.45; p=0.020), and polypharmacy (OR 10.41, 95% CI 1.85-59.38; p=0.008).

Conclusion: A high prevalence of comorbidity was found in IBD, possibly related to low socioeconomic status and poor educational level.