Adherence and Clinical Effectiveness of a Subcutaneous Insulin Clinical Decision Support Tool in Hospitalized Patients

Background: Inpatient hyperglycemia is common and associated with adverse outcomes. Subcutaneous insulin remains the mainstay of treatment for most non-critically ill patients, yet appropriate dosing is complex and prone to variation. Clinical decision support (CDS) tools may improve insulin prescribing, but few have been evaluated in real-world settings. Methods: We conducted a retrospective cohort study of adult inpatients with diabetes and hyperglycemia admitted to 2 academic medical centers between December 1, 2015, and July 30, 2018. We assessed uptake, effectiveness, and adherence to an optional subcutaneous insulin CDS tool embedded in the Epic electronic medical record (EMR). Propensity score matching with Crump trimming and 1:3 nearest-neighbor matching was used to compare glycemic outcomes between patients who used the tool within 24 hours of admission and matched controls. Results: Of 5485 eligible admissions, 662 (12.1%) involved tool use on day 1. Tool use was more common among patients with type 1 diabetes, chronic kidney disease, or higher baseline glucose and varied by diagnosis and provider type. Among matched patients (n = 1750), tool use was associated with greater odds of any euglycemia (70-180 mg/dL) on day 2 (75.1% vs 69.8%; odds ratio [OR] = 1.30, 95% CI = 1.04-1.63; P = .02). Mean glucose levels, hypoglycemia, and hyperglycemia did not differ significantly. Only 43.7% of patients for whom the tool was used received a total daily insulin dose within 20% of the user-selected dose. Conclusion: Use of an EMR-integrated insulin CDS tool was associated with modest glycemic improvements. Low adherence may have attenuated its clinical impact.