Comorbidities Associated with Worse Outcomes Among Inpatients Admitted for Acute Gastrointestinal Bleeding

BACKGROUND: Multimorbidity increases healthcare resource utilization. Little is known on specific comorbidity combinations. AIMS: To identify comorbidities associated with increased resource utilization among inpatients admitted for gastrointestinal bleeding (GIB). METHODS: This retrospective cross-sectional study, 1/2010–5/2018 at the University Hospital Zurich, Switzerland, analyzed electronic health records of patients with upper (UGIB) and lower (LGIB) GIB, focusing on length of stay (LOS) and 30-day readmissions for resource use and clinical outcomes, investigated by multivariable regression adjusted for antithrombotics. RESULTS: Of 1101 patients, 791 had UGIB and 310 LGIB, most often melena and bleeding diverticula, respectively. In UGIB, thromboembolic events showed a trend toward 27% increased LOS (1.27; 95% confidence interval [CI] 1.00–1.61), antithrombotics independently associated with 46% increased LOS (1.46; 95% CI 1.32–1.62). Cancer (odds ratio [OR] 2.86; 95% CI 1.68–4.88) independently associated with 30-day readmissions, anemia showed a trend (OR 1.68; 95% CI 1.00–2.84). In LGIB, none of the investigated comorbidities associated with increased LOS, but antithrombotics independently associated with 25% increased LOS (1.25; 95% CI 1.07–1.46). Atrial fibrillation/flutter (OR 2.69; 95% CI 1.06–6.82) and cancer (OR 4.76; 95% CI 1.40–16.20) associated strongly with 30-day readmissions. CONCLUSIONS: In both groups, cancer associated with 30-day readmissions, antithrombotics with increased LOS. Thromboembolic events and anemia showed clinically important trends in UGIB. Atrial fibrillation/flutter associated with 30-day readmissions in LGIB. Prospective studies are needed to investigate these complex multimorbid populations and establish appropriate guidelines. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10620-021-07197-7.