Telephone interventions may improve HbA1c control in low-income populations

The addition of telephone calls by health educators to printed self-management materials may improve diabetes control in low-income diabetics with worse metabolic control, a study found.

The randomized, controlled trial tested the effectiveness of a telephone behavioral intervention among adults with diabetes and HbA1c levels >7% in the New York City A1c Registry. Patients came from a low-income, predominantly Latino population in the South Bronx. All study participants were mailed print diabetes self-management materials at baseline and modest lifestyle incentives quarterly. The intervention group also received calls from health educators evenly spaced over 1 year, 4 calls if their baseline HbA1c was >7% to 9% or 8 calls if their baseline HbA1c was >9%.

The primary outcome was the change in HbA1c from baseline to 1 year. Secondary outcomes included diabetes self-care activities, including self-reported medication adherence. Data were collected from 2008 to 2012 and analyzed from 2012 to 2014. Results were published online July 29 by the American Journal of Preventive Medicine.

Among 694 (74%) participants with available follow-up, mean HbA1c decreased by 0.9 percentage point (SD, 0.1) among the telephone group (n=334) compared with 0.5 percentage point (SD, 0.1) among the print-only group (n=360), a difference of 0.4 percentage point (95% CI, 0.09 to 0.74, P=0.01). In addition to a greater decrease in mean HbA1c in the intervention group, the percentage of participants in the telephone arm who had an HbA1c decrease of at least 1 percentage point or 1.5 percentage points at the end of the study was 37.4% and 26.7%, respectively, compared with 28.3% and 19.2% in the print-only arm, respectively (P=0.01 and 0.02 for between-group differences).

The biggest effect was in the patients with a baseline HbA1c >9.0%, who experienced a decrease of 2.1 percentage points in the telephone arm and 1.3 percentage points print-only arm. In patients with initial HbA1c ≤9%, there was no change in HbA1c in the telephone arm and an increase of 0.2 percentage point in the print arm.

Over the course of this study, telephone participants in the >7% to 9% HbA1c tier engaged in a mean of 3.4 calls (protocol maximum was 4) and those in the >9% HbA1c tier had a mean of 6.3 calls (protocol maximum was 8). The total duration of intervention calls in the telephone arm averaged 109.8 minutes over 12 months and increased in relation to baseline HbA1c. The average total number of minutes was 85.5 for those with baseline HbA1c ≤9% and 144.7 for those with a baseline HbA1c >9%.

“Readily accessible, low-cost programs to support medication adherence and lifestyle behaviors are critical for improving glycemic control across all populations,” the authors concluded. “A tailored telephone intervention such as the program we implemented has the potential for wide-scale use, particularly for those with poor metabolic control (A1c >9%), in the environment of a registry or other population health management system such as a patient-centered medical home.”