Abstract / Summary
Background: Digital diabetes programs have expanded quickly, but evidence of durable long-term benefit remains limited. In addition, as diabetes treatment guidelines changed to include cardiorenal-protective antihyperglycemics as first-line therapy, the effects of their adoption on glycemic control and program engagement within these programs remain poorly understood. Objective: To characterize longitudinal trends in glycemic control and estimate the extent to which these trends are associated with time-invariant and time-varying domains, among adults with T2D participating in Teladoc Health Remote Diabetes Monitoring Program (RDMP). Methods: This was a retrospective, longitudinal cohort study of adults with T2D participating in the Teladoc RDMP from 2021-2025. Domains were split into time-invariant (i.e. demographics and baseline clinical characteristic) and time-varying covariates (e.g. antihyperglycemic treatment complexity and adherence, program utilization and engagement, and adoption of cardiorenal protective antihyperglycemics). Primary outcome was estimated A1c (eA1c), calculated from FBG measurements captured through cellular-enable smart glucose meters. Longitudinal mixed-effects models were used to estimate adjusted annual trends in eA1c over 5 years, and Gelbach decomposition to quantify statistical contributions across domains. Secondary analyses examined attainment of eA1c <7% using GEE and complementary decomposition methods. Results: A total of 56,754 members with mean age 64.2 (SD 10.4), and 49% female were included in the analysis. Mean eA1c declined by 0.06 percentage points per year (95% CI, -0.06 to -0.06) and remained significantly lower after full adjustment for demographic, antihyperglycemic treatment and cardiorenal-protective therapy adherence, and program engagement factors ({beta}=-.04 percentage points/year; 95% CI, -.04 to -.03), demonstrating durable glycemic improvement over the five-year study period. Gelbach decomposition attributed most of the change between the base and fully adjusted trends to cardiorenal-protective therapies (170.8%), with an opposing contribution from program engagement (-71.9%) and minimal contribution from treatment history and complexity (1.1%). Adjusted odds of attaining eA1c <7% increased 8.0% annually (OR 1.08; 95% CI 1.07-1.09), corresponding to a 1.21-percentage-point annual increase in probability; adjusted predicted glycemic control increased from 75.2% in 2021 to 80.1% in 2025. Conclusion: In this five-year cohort, members who remained in the RDMP sustained improvements in eA1c and became more likely to reach an eA1c < 7%. Cardiorenal protective antihyperglycemics made the largest measured contribution to these trends, while program engagement contributed in the opposite direction. These findings show durable glycemic control but does not establish causal effects. Future evaluations of digital diabetes programs should account for pharmacotherapy, durability of improvements, and measure outcomes across cardiometabolic health.