Patterns of Telemedicine Use and Glycemic Outcomes of Endocrinology Care for Patients with Type 2 Diabetes

Importance: Telemedicine can increase access to endocrinology care for people with type 2 diabetes (T2D), but patterns of use and outcomes of telemedicine specialty care for adults with T2D beyond initial uptake in 2020 are not known. Objective: To evaluate patterns of telemedicine use and their association with glycemic control among adults with varying clinical complexity receiving endocrinology care for T2D. Design, Setting, and Participants: Retrospective cohort study in a single large integrated US health system. Participants were adults who had a telemedicine endocrinology visit for T2D from May to October 2020. Data were analyzed from June 2022 to October 2023. Exposure: Patients were followed up through May 2022 and assigned to telemedicine-only, in-person, or mixed care (both telemedicine and in-person) cohorts according to visit modality. Main Outcomes and Measures: Multivariable regression models were used to estimate hemoglobin A_1c(HbA_1c) change at 12 months within each cohort and the association of factors indicating clinical complexity (insulin regimen and cardiovascular and psychological comorbidities) with HbA_1cchange across cohorts. Subgroup analysis was performed for patients with baseline HbA_1cof 8% or higher. Results: Of 11498 potentially eligible patients, 3778 were included in the final cohort (81 Asian participants [2%], 300 Black participants [8%], and 3332 White participants [88%]); 1182 used telemedicine only (mean [SD] age 57.4 [12.9] years; 743 female participants [63%]), 1049 used in-person care (mean [SD] age 63.0 [12.2] years; 577 female participants [55%]), and 1547 used mixed care (mean [SD] age 60.7 [12.5] years; 881 female participants [57%]). Among telemedicine-only patients, there was no significant change in adjusted HbA_1cat 12 months (-0.06%; 95% CI, -0.26% to 0.14%; P =.55) while in-person and mixed cohorts had improvements of 0.37% (95% CI, 0.15% to 0.59%; P <.001) and 0.22% (95% CI, 0.07% to 0.38%; P =.004), respectively. Patients with a baseline HbA_1cof 8% or higher had a similar pattern of glycemic outcomes. For patients prescribed multiple daily injections vs no insulin, the 12-month estimated change in HbA_1cwas 0.25% higher (95% CI, 0.02% to 0.47%; P =.03) for telemedicine vs in-person care. Comorbidities were not associated with HbA_1cchange in any cohort. Conclusions and Relevance: In this cohort study of adults with T2D receiving endocrinology care, patients using telemedicine alone had inferior glycemic outcomes compared with patients who used in-person or mixed care.