Trends and Determinants of Inpatient Colonoscopy Use and Timing in Adults Hospitalized with Ischemic Colitis: A National Analysis, 2017-2022.

BACKGROUND: Colonoscopy is a guideline-recommended diagnostic test in suspected ischemic colitis, but national patterns of inpatient colonoscopy use and timing have not been well described in recent years. METHODS: We analyzed the National Inpatient Sample from 2017 through 2022. Adults with a principal discharge diagnosis of ischemic colitis were included, and interhospital transfers were excluded. The primary outcome was the annual proportion of hospitalizations undergoing inpatient colonoscopy; the secondary outcome was the proportion undergoing colonoscopy within 48 h among patients with ischemic colitis who underwent colonoscopy. Survey-weighted logistic regression assessed annual trends and independent patient, illness severity, and hospital factors associated with each outcome. Mortality and colectomy were summarized as descriptive context. RESULTS: The weighted cohort comprised 132,455 admissions. Colonoscopy was performed in 42.0% (95% CI 41.3-42.6), and the annual rate fell from 44.7% in 2017 to 40.2% in 2022 (P = 0.0001); after adjustment for demographics, comorbidities, illness-severity markers, and hospital characteristics, colonoscopy probability decreased by 0.80 percentage points per year (95% CI - 1.18 to -0.41). Among admissions with valid procedure-day information, 72.4% underwent colonoscopy within 48 h, with no significant annual variation (P = 0.069). Colonoscopy use decreased with illness severity, from 43.3% in low-acuity admissions to 14.7% in the highest-acuity stratum, and remained lower at rural than at urban hospitals, even among low-acuity patients (37.1% vs 43.8%). Lower adjusted odds of inpatient colonoscopy were associated with sepsis, mechanical ventilation, rural hospital location, and the Northeast region. Lower adjusted odds of colonoscopy within 48 h were associated with weekend admission, Black race, Medicaid payer status, and several illness-severity markers. CONCLUSIONS: Inpatient colonoscopy use in ischemic colitis declined modestly between 2017 and 2022, while timing among patients undergoing colonoscopy remained stable. Use and timing varied across measured illness severity, hospital, regional, and sociodemographic characteristics. Differences in timing across race and payer groups warrant further study to determine whether they reflect inequities in care or other unmeasured clinical and health-system factors.