Telephone-Delivered Behavioral Skills Intervention for African American Adults with Type 2 Diabetes: A Randomized Controlled Trial

Abstract

Background: Diabetes disproportionately affects African Americans and is associated with poorer outcomes. Self-management is important for glycemic control; however, evidence in African Americans is limited.

Objective: To assess the efficacy of a combined telephone-delivered education and behavioral skills intervention (TBSI) in reducing hemoglobin A1c (HbA1c) levels in African Americans with type 2 diabetes, using a factorial design.

Design: This is a four-year randomized clinical trial, using a 2 x 2 factorial design.: Participants: African American adults ≥18 years) with poorly controlled type 2 diabetes (HbA1c ≥9%) were randomly assigned to one of four groups: 1) knowledge only, 2) skills only, 3) combined knowledge and skills (TBSI), or 4) control group.

Intervention: All participants received 12 telephone-delivered 30-min intervention sessions specific to their assigned group. Participants were assessed at baseline and 3, 6, and 12 months.

Main measure: The primary outcome was HbA1c at 12 months post-randomization in the intent-to-treat (ITT) population.

Key results: Two hundred fifty-five participants were randomly assigned to the four groups. Based on the ITT population after multiple imputation, the analysis of covariance with baseline HbA1c as the covariate showed that HbA1c at 12 months for the intervention groups did not differ significantly from that of the control group (knowledge: 0.49, p = 0.123; skills: 0.23, p = 0.456; combined: 0.48, p = 0.105). Absolute change from baseline at 12 months for all treatment arms was 0.6. Longitudinal mixed effects analysis showed that, on average, there was a significant decline in HbA1c over time for all treatment groups (-0.07, p < 0.001). However, the rates of decline for the intervention groups were not significantly different from that of the control group (knowledge: 0.06, p = 0.052; skills: 0.02, p = 0.448; combined: 0.05, p = 0.062). Results from per-protocol populations were similar.

Conclusions: For African Americans with poorly controlled type 2 diabetes, combined education and skills training did not achieve greater reductions in glycemic control (i.e., HbA1c levels) at 12 months compared to the control group, education alone, or skills training alone. This trial is registered with ClinicalTrials.gov, identifier no. NCT00929838.

Conflict of interest statement

The authors declare that they do not have a conflict of interest.

Figures

Figure 1

Trial profile (CONSORT diagram).

Figure 2

Mean levels of hemoglobin A1c over time by treatment group.