Impact of Peer Health Coaching on Glycemic Control in Low-Income Patients With Diabetes: A Randomized Controlled Trial

PURPOSE: Peer health coaches offer a potential model for extending the capacity of primary care practices to provide self-management support for patients with diabetes. We conducted a randomized controlled trial to test whether clinic-based peer health coaching, compared with usual care, improves glycemic control for low-income patients who have poorly controlled diabetes. METHOD: We undertook a randomized controlled trial enrolling patients from 6 public health clinics in San Francisco. Twenty-three patients with a glycated hemoglobin (HbA1C) level of less than 8.5%, who completed a 36-hour health coach training class, acted as peer coaches. Patients from the same clinics with HbA1C levels of 8.0% or more were recruited and randomized to receive health coaching (n = 148) or usual care (n = 151). The primary outcome was the difference in change in HbA1C levels at 6 months. Secondary outcomes were proportion of patients with a decrease in HbA1C level of 1.0% or more and proportion of patients with an HbA1C level of less than 7.5% at 6 months. Data were analyzed using a linear mixed model with and without adjustment for differences in baseline variables. RESULTS: At 6 months, HbA1C levels had decreased by 1.07% in the coached group and 0.3% in the usual care group, a difference of 0.77% in favor of coaching (P = .01, adjusted). HbA1C levels decreased 1.0% or more in 49.6% of coached patients vs 31.5% of usual care patients (P = .001, adjusted), and levels at 6 months were less than 7.5% for 22.0% of coached vs 14.9% of usual care patients (P = .04, adjusted). CONCLUSIONS: Peer health coaching significantly improved diabetes control in this group of low-income primary care patients.