C-PEPTIDE AND BETA-CELL AUTOANTIBODY TESTING PRIOR TO INITIATING CONTINUOUS SUBCUTANEOUS INSULIN INFUSION PUMP THERAPY DID NOT IMPROVE UTILIZATION OR MEDICAL COSTS AMONG OLDER ADULTS WITH DIABETES MELLITUS.

OBJECTIVE: To study the impact of the C-peptide and beta-cell autoantibody testing required by the Center for Medicare and Medicaid Services (CMS) on costs/utilization for patients with diabetes mellitus initiating continuous subcutaneous insulin infusion (CSII) therapy.

METHODS: This retrospective study used propensity score-matched patients. Analysis 1 compared patients 1-year pre- and 2-years post-CSII adoption who met or did not meet CMS criteria. Analysis 2 compared Medicare Advantage patients using CSII or multiple daily injections (MDI) who did not meet CMS criteria for 1-year pre- and 1-year post-CSII adoption. Analysis 3 extended analysis 2 to 2 years postindex and also included a subset of patients ≥55 years old but not yet in Medicare Advantage.

RESULTS: Analysis 1 resulted in significantly slower growth in hospital admissions ( P = .0453) in CSII-treated patients who did not meet the criteria. Analyses 2 and 3 showed numerically slower growth in inpatient, outpatient, and emergency department (ED) costs for CSII versus MDI patients (both not meeting criteria). Analysis 3 showed significantly slower growth in ED costs and hospital admissions for CSII versus MDI Medicare Advantage patients before propensity matching (both P<.05). In patients ≥55 years old, ED costs grew more slowly for CSII than MDI therapy ( P = .0678).

CONCLUSION: Numerically slower growth in hospital admissions was seen for pump adopters who did not meet CMS C-peptide criteria, while medical costs growth was similar. For CSII users who did not meet the CMS criteria, numerically slower growth in inpatient, outpatient, ED costs, and hospital admissions occurred versus MDI.

ABBREVIATIONS: CMS = Center for Medicare and Medicaid Services; CSII = continuous subcutaneous insulin infusion; DM = diabetes mellitus; DME = durable medical equipment; ED = emergency department; MDI = multiple daily injections (of insulin).