Telephone Intervention to Improve Diabetes Control: A Randomized Trial in the New York City A1c Registry

Introduction Scalable self-management interventions are necessary to address suboptimal diabetes control, especially among minority populations. The study tested the effectiveness of a telephone behavioral intervention in improving glycemic control among adults with diabetes in the New York City A1c Registry. Design RCT comparing a telephone intervention to print-only intervention in the context of the A1c Registry program. Setting/participants Nine hundred forty-one adults with diabetes and hemoglobin A1c (A1c) >7% from a low-income, predominantly Latino population in the South Bronx were recruited from the A1c Registry. Intervention All study participants were mailed print diabetes self-management materials at baseline and modest lifestyle incentives quarterly. Only the telephone participants received four calls from health educators evenly spaced over 1 year if baseline A1c was >7%–9%, or eight calls if baseline A1c was >9%. Medication adherence was the main behavioral focus and, secondarily, nutrition and exercise. Main outcome measures Primary outcome was difference between two study arms in change in A1c from baseline to 1 year. Secondary outcomes included diabetes self-care activities, including self-reported medication adherence. Data were collected in 2008–2012 and analyzed in 2012–2014. Results Participants were predominantly Latino (67.7%) or non-Latino black (28%), with 69.7% foreign-born and 55.1% Spanish-speaking. Among 694 (74%) participants with follow-up A1c, mean A1c decreased by 0.9 (SD=0.1) among the telephone group compared with 0.5 (SD=0.1) among the print-only group, a difference of 0.4 (95% CI=0.09, 0.74, p =0.01). The intervention had significant effect when baseline A1c was >9%. Both groups experienced similar improvements in self-care activities, medication adherence, and intensification. Conclusions A telephone intervention delivered by health educators can be a clinically effective tool to improve diabetes control in diverse populations, specifically for those with worse metabolic control identified using a registry. This public health approach could be adopted by health systems supported by electronic record capabilities. ClinicalTrials.gov Registration NCT00797888.