Frailty and geriatric complications in older patients with IBD: a nationwide hospital claims database study across Japan

Abstract

Background

Older patients with inflammatory bowel disease (IBD) often have multimorbidity and functional vulnerability, which increases the risk of in-hospital complications. This study examined whether frailty at admission is associated with hospital-associated geriatric complications in this population.

Methods

This retrospective cohort study was conducted using a nationwide hospital-based claims database in Japan. Patients aged ≥ 60 years hospitalized with ulcerative colitis or Crohn’s disease between February 2014 and September 2025 were identified. Frailty was assessed using the Hospital Frailty Risk Score (HFRS ≥ 5). The primary outcome was hospital-associated complications in older people (HAC-OP), which is a composite of functional decline, incontinence, delirium, pressure injury, and falls/fractures. The risk ratios (RRs) and 95% confidence intervals (CIs) were estimated using modified Poisson regression.

Results

Among 3,905 hospitalizations, 1,220 (31.2%) patients were classified as frail. Overall, 6.7% of hospitalizations were complicated by at least one HAC-OP, with a higher incidence in patients with frailty than in non-frail patients (10.7% vs. 4.8%). Frailty was associated with HAC-OP (adjusted RR 1.74, 95% CI 1.36–2.21), functional decline (adjusted RR 1.54, 95% CI 1.12–2.11), and delirium (adjusted RR 2.50, 95% CI 1.66–3.76). Results were robust in sensitivity analyses using multiple imputation, additional adjustment for length of stay.

Conclusions

In hospitalized older patients with IBD, frailty at admission was associated with hospital-associated geriatric complications, particularly delirium and functional decline. The HFRS may be a useful tool for identifying patients at higher risk, and future studies should evaluate whether frailty-targeted interventions can reduce these complications.