Impact of Pharmacist Consultations in Management of Type 1 Diabetes in a Primary Care Clinic: A Retrospective Cohort Study

Abstract

Introduction: Type 1 diabetes mellitus (T1DM) is a condition requiring lifelong insulin therapy and specialized care. Access to endocrinologists remains limited, leaving many primary care providers (PCPs) to manage insulin therapies and diabetes technologies. Pharmacists have demonstrated effectiveness in type 2 diabetes management, yet their role in T1DM within primary care remains underexplored. This study evaluated the impact of a pharmacist-led intervention for adults with T1DM in a primary care setting lacking in-house endocrinology services. Methods: This retrospective cohort study reviewed electronic health records of adults with T1DM referred to a clinical pharmacist in 2023. Individuals with ≥2 PCP visits, ≥2 A1c results, and ≥1 pharmacist consultation were included. The pharmacist provided individualized assessments, insulin adjustments, and technology counseling under a collaborative practice agreement. The primary outcome was change in A1c at 3-6 months post-consultation. Secondary outcomes included subgroup analyses by insulin delivery methods, visit frequencies and A1c comparison with non-referred T1DM patients. Results: Thirty-eight patients met inclusion criteria. Referred patients experienced a mean A1c reduction from 8.8% to 8.2% (−0.6%, 95% CI: −1.00 to −0.12; P = .013) at 3-6 months. No significant differences were observed in continuous glucose monitoring metrics or visit frequency. Compared with 49 non-referred patients, referred individuals initially had poorer glycemic control but showed convergence over time. Discussion: Pharmacist integration into primary care significantly improved glycemic outcomes for adults with T1DM, particularly in underserved regions with limited endocrinology access. This collaborative model may offer a scalable solution to expand advanced diabetes management in primary care.