Adherence to diabetes self care is poor for Hispanic American and African-American patients. This study examined the change in adherence over time and in response to a telemedicine intervention for elderly diabetes patients in these groups compared to white diabetes patients. We also examined whether adherence mediated the effect of the intervention on glycemic control (A1c).
The Informatics for Diabetes Education and Telemedicine project randomized medically underserved Medicare patients (n=1665) to telemedicine case management (tele-video educator visits, individualized goal-setting/problem solving) or usual care. Hispanic and African-American educators delivered the intervention in Spanish if needed.
Main Outcome Measures
Annual assessment included A1c and self-reported adherence (Summary of Diabetes Self-Care Activities scale). A simple model (only time and group terms) and a model with covariates (e.g., age) were examined for baseline and 5 years of follow-up. SAS PROC Mixed was used with non-linear terms to examine mediating effects of adherence on A1c, by performing tests of the mediating path coefficients.
Over time, self-reported adherence improved for the treatment group compared to usual care (p<0.001). There was no significant interaction with racial/ethnic group membership, i.e., all groups improved. However, minority subjects were consistently less adherent than whites. Also, greater comorbidity and diabetes symptoms predicted poorer adherence, greater duration of diabetes and more years of education predicted better adherence. Adherence was a significant mediator of A1c (p<0.001).
A unique, tailored telemedicine intervention was effective in achieving improved adherence to diabetes self care. However, African-American and Hispanic American participants were less adherent than white participants at all time points despite an individualized and accessible intervention. The finding that adherence did mediate glycemic control suggests that unique interventions for minority groups may be needed to overcome this disparity.