Administratively Defined Functional Vulnerability and Adverse Short-Term Outcomes in Older Adults Hospitalized with Crohn’s Disease Flares: A Propensity-Matched Multicenter Cohort Study

Background/Objectives: Functional vulnerability may identify older adults hospitalized with Crohn’s disease flares who are at increased risk for adverse outcomes, but its prognostic significance in this setting remains incompletely defined. We evaluated the association between administratively defined functional vulnerability, identified using administrative diagnostic codes, and short-term clinical outcomes among adults aged ≥65 years hospitalized with Crohn’s disease flares. Methods: We conducted a retrospective cohort study using the TriNetX US Collaborative Research Network through February 2026. Functional vulnerability was identified using ICD-10-CM codes for frailty, sarcopenia, cachexia, abnormal weight loss, muscle weakness, gait/mobility abnormalities, or reduced mobility within 12 months before or during the index hospitalization. Patients coded only for nonspecific weakness or fatigue were excluded from the functional vulnerability cohort. Patients underwent 1:1 propensity score matching using demographic, comorbidity, Crohn’s disease-related, medication, nutritional, and laboratory variables. The primary outcome was 30-day all-cause mortality. Results: Among 18,420 eligible patients, 2846 met criteria for functional vulnerability, and 15,574 did not. After matching, 2720 patients remained in each cohort. Functional vulnerability was associated with higher 30-day mortality (RR 1.61, 95% CI 1.21–2.14), 90-day mortality (RR 1.40, 95% CI 1.14–1.72), bowel surgery (RR 1.29, 95% CI 1.07–1.56), sepsis (RR 1.41, 95% CI 1.18–1.68), acute kidney injury (RR 1.26, 95% CI 1.10–1.44), ICU admission (RR 1.32, 95% CI 1.13–1.55), TPN use (RR 1.47, 95% CI 1.20–1.79), and 90-day readmission (RR 1.17, 95% CI 1.07–1.29). Functionally vulnerable patients also had longer hospital stays (8.9 vs. 6.7 days; mean difference 2.2 days, 95% CI 1.9–2.5). Conclusions: Administratively defined functional vulnerability identified through diagnostic coding was associated with worse short-term outcomes among older adults hospitalized with Crohn’s disease flares. Although functional vulnerability is a recognized predictor of adverse outcomes across hospitalized populations broadly, these findings quantify its prognostic significance specifically in Crohn’s disease flare hospitalizations and suggest that functional vulnerability may identify a high-risk geriatric IBD phenotype that could benefit from early multidisciplinary assessment, nutritional optimization, rehabilitation planning, and post-discharge care coordination.