Obesity in Inflammatory Bowel Disease Is Associated with Early Readmissions Characterised by an Increased Systems and Patient-level Burden

BACKGROUND AND AIMS: Rates of obesity are rising in patients with inflammatory bowel disease [IBD]. We conducted a US population-based study to determine the effects of obesity on outcomes in hospitalised patients with IBD. METHODS: We searched the Nationwide Readmissions Database 2016-2017 to identify all adult patients hospitalised for IBD, using ICD-10 codes. We compared obese (body mass index [BMI] ≥ 30) vs non-obese [BMI < 30] patients with IBD to evaluate the independent effects of obesity on readmission, mortality, and other hospital outcomes. Multivariate regression and propensity matching were performed. RESULTS: We identified 143 190 patients with IBD, of whom 9.1% were obese. Obesity was independently associated with higher all-cause readmission at 30 days {18% vs 13% (adjusted odds ratio [aOR] 1.16, p = 0.005)} and 90 days (29% vs 21% [aOR 1.27, p < 0.0001]), as compared with non-obese patients, with similar findings upon a propensity-matched sensitivity analysis. Obese and non-obese patients had similar risks of mortality on index admission [0.24% vs 0.31%, p = 0.18] and readmission [1.5% vs 1.8% p = 0.3]. Obese patients had longer [5.3 vs 4.9 days] and more expensive [USD12,195 vs USD11,154] hospitalisations on index admission. Obesity did not affect the risk of intestinal surgery or bowel obstruction. Compared with index admissions, readmissions were characterised by increased mortality [6-fold], health care use, and bowel obstruction [3-fold] [all p < 0.0001]. CONCLUSIONS: Obesity in IBD appears to be associated with increased early readmission, characterised by a higher burden, despite the introduction of weight-based therapeutics. Prevention of obesity should be a focus in the treatment of IBD to decrease readmission and health care burden.