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 A1c (HbA1c) change at 12 months within each cohort and the association of factors indicating clinical complexity (insulin regimen and cardiovascular and psychological comorbidities) with HbA1c change across cohorts. Subgroup analysis was performed for patients with baseline HbA1c of 8% or higher. Results: Of 11 498 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 HbA1c at 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 HbA1c of 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 HbA1c was 0.25% higher (95% CI, 0.02% to 0.47%; P = .03) for telemedicine vs in-person care. Comorbidities were not associated with HbA1c change 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. Additional strategies may be needed to support adults with T2D who rely on telemedicine alone to access endocrinology care, especially for those with complex treatment or elevated HbA1c.