Insulin Pump Use and Hospital Outcomes in Adults With Type 1 Diabetes: A 2022 Nationwide Readmissions Database Analysis

CONTEXT: Adults with type 1 diabetes (T1D) experience substantial inpatient morbidity, including frequent readmissions and measurable in-hospital mortality, contributing significantly to U.S. health care utilization. OBJECTIVE: To evaluate the association between insulin delivery modality and 30-day readmission and in-hospital mortality among adults hospitalized with T1D. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study using the 2022 Nationwide Readmissions Database, a nationally representative all-payer inpatient database. Adults (≥18 years) hospitalized with T1D were identified using ICD-10-CM codes. Index admissions were defined as the first eligible hospitalization per patient within the calendar year; December and elective admissions were excluded to ensure complete 30-day follow-up. EXPOSURE: Insulin pump therapy (± injectable insulin) versus injectable insulin only. Primary outcome was time to first all-cause readmission within 30 days. Secondary outcomes included in-hospital mortality during index admission and readmission. Survey-weighted Cox and logistic regression models estimated adjusted hazard ratios (aHRs) and odds ratios (aORs). RESULTS: The weighted cohort included 230,958 adult index admissions. Thirty-day readmission occurred in 14.64% of pump users versus 20.63% of injectable-only users. After multivariable adjustment, pump therapy was associated with lower readmission risk (aHR, 0.77; 95% CI, 0.74-0.81; P < 0.001). In secondary analyses, this association persisted for 90-day readmission outcomes. In-hospital mortality during index admission was lower among pump users (0.90% [95% CI, 0.78-1.05]) compared with injectable-only users (1.31% [95% CI, 1.21-1.42]). Pump therapy remained associated with reduced mortality (aOR, 0.78; 95% CI, 0.66-0.93; P = 0.006). CONCLUSION: In this nationally representative cohort, insulin pump therapy was independently associated with lower 30-day readmission and in-hospital mortality among adults with T1D.