Insulin Pump Therapy and Its Impact on Hospital Readmissions and Mortality in Adults with Type 1 Diabetes: Insights from a 2022 Nationwide Analysis

Highlight

• Insulin pump therapy is independently associated with a 23% reduction in 30-day hospital readmissions among adults with type 1 diabetes compared to injectable insulin alone.
• In-hospital mortality was lower in insulin pump users, with a 22% adjusted reduction in odds of death during index admission.
• The 2022 Nationwide Readmissions Database provides a nationally representative insight into inpatient outcomes linked to insulin delivery modality in type 1 diabetes.

Study Background and Disease Burden

Type 1 diabetes (T1D) is a chronic autoimmune disorder characterized by insulin deficiency, necessitating lifelong insulin replacement. Adults with T1D frequently face significant inpatient morbidity, including high rates of hospitalization and readmissions, often related to acute metabolic complications such as diabetic ketoacidosis (DKA) and severe hypoglycemia. These hospitalizations contribute substantially to healthcare utilization and costs in the United States. Effective diabetes management is pivotal to reducing these adverse outcomes and improving patient survival.

Insulin delivery modalities have evolved with the increasing use of insulin pumps, which provide continuous subcutaneous insulin infusion. Prior observational studies and clinical trials suggest that insulin pump therapy may improve glycemic control and reduce hypoglycemic episodes compared to multiple daily injections (MDI). However, large-scale data evaluating the inpatient clinical outcomes associated with these modalities remain limited, particularly regarding readmission rates and mortality.

Study Design

This retrospective cohort study utilized the 2022 Nationwide Readmissions Database (NRD), which is an all-payer inpatient database representative of U.S. hospitalizations. Adults aged 18 years and older hospitalized with a primary or secondary diagnosis of T1D, identified by ICD-10-CM codes, were included. The study focused on index admissions, defined as the first eligible hospitalization per patient in the calendar year, excluding elective and December admissions to ensure a full 30-day follow-up period.

The exposure groups were classified based on insulin delivery methods coded during hospitalization: insulin pump therapy (with or without concomitant injectable insulin) versus injectable insulin only.

The primary outcome was time to first all-cause readmission within 30 days after discharge from the index admission. Secondary outcomes included in-hospital mortality during both the index admission and any readmission within 30 days.

Statistical analyses incorporated survey-weighted Cox proportional hazards models to calculate adjusted hazard ratios (aHRs) for readmission, and logistic regression models to estimate adjusted odds ratios (aORs) for mortality, accounting for confounding variables including demographics, comorbidity burden, hospital characteristics, and admission details.

Key Findings

The weighted cohort comprised 230,958 index admissions of adults with T1D. Among these, 14.64% of patients using insulin pumps were readmitted within 30 days compared to 20.63% in the injectable insulin-only group. After multivariable adjustment, insulin pump therapy was significantly associated with a 23% lower hazard of 30-day readmission (aHR 0.77; 95% CI, 0.74–0.81; P < 0.001).

Secondary analyses extending to 90-day readmissions confirmed the persistent benefit of pump therapy, supporting its role in longer-term post-discharge outcomes.

Regarding in-hospital mortality, pump users exhibited a lower mortality rate during the index admission (0.90%; 95% CI, 0.78–1.05) compared to those receiving injectable insulin only (1.31%; 95% CI, 1.21–1.42). Adjusted analyses demonstrated a 22% reduction in the odds of mortality with insulin pump therapy (aOR 0.78; 95% CI, 0.66–0.93; P = 0.006).

These findings collectively indicate that insulin pump usage in T1D is associated with improved inpatient outcomes, reducing both the likelihood of readmission and risk of death during hospitalization.

Expert Commentary

This large-scale analysis reinforces previously reported benefits of insulin pump therapy in the outpatient setting by extending its positive impact to hospital outcomes. The physiologic advantages of continuous subcutaneous insulin infusion—such as improved glycemic stability and avoidance of wide glucose excursions—likely underpin these findings.

Nonetheless, it is essential to note that observational data cannot conclusively establish causality. Residual confounding by indication or patient characteristics not fully captured in administrative data (e.g., socioeconomic status, diabetes duration, adherence, or diabetes education) might influence results.

Further prospective studies and randomized trials could validate these results and elucidate the mechanisms by which insulin pump therapy confers inpatient benefits.

Conclusion

This nationally representative study highlights that insulin pump therapy among adults with type 1 diabetes is associated with significantly lower 30-day hospital readmission rates and reduced in-hospital mortality compared to injectable insulin only. These findings support the broader use of insulin pumps to improve clinical outcomes and may inform healthcare policy and diabetes management strategies aimed at reducing healthcare utilization and improving survival in this patient population.

Funding and ClinicalTrials.gov

The original study does not report specific funding sources or clinical trial registration details.

References

• Reguram R, Shah R, Vora T, et al. Insulin Pump Use and Hospital Outcomes in Adults With Type 1 Diabetes: A 2022 Nationwide Readmissions Database Analysis. J Clin Endocrinol Metab. 2026 Jul 30; PMID: 42530032.
• Bergenstal RM, et al. Effectiveness of Sensor-Augmented Insulin-Pump Therapy in Type 1 Diabetes. N Engl J Med. 2010;363(4):311-320.
• Nathan DM, et al. Diabetes Control and Complications Trial Research Group. Intensive Diabetes Treatment and Cardiovascular Disease in Patients with Type 1 Diabetes. N Engl J Med. 2005;353:2643-2653.