Results of a successful telephonic intervention to improve diabetes control in urban adults: a randomized trial

Abstract

Objective: To compare the effectiveness of a telephonic and a print intervention over 1 year to improve diabetes control in low-income urban adults.

Research design and methods: A randomized trial in Spanish and English comparing a telephonic intervention implemented by health educators with a print intervention. Participants (N = 526) had an A1C ≥7.5% and were prescribed one or more oral agents. All were members of a union/employer jointly sponsored health benefit plan. Health coverage included medications. Primary outcomes were A1C and pharmacy claims data; secondary outcomes included self-report of two medication adherence measures and other self-care behaviors.

Results: Participants were 62% black and 23% Hispanic; 77% were foreign born, and 42% had annual family incomes <$30 thousand. Baseline median A1C was 8.6% (interquartile range 8.0-10.0). Insulin was also prescribed for 24% of participants. The telephone group had mean ± SE decline in A1C of 0.23 ± 0.11% over 1 year compared with a rise of 0.13 ± 0.13% for the print group (P = 0.04). After adjusting for baseline A1C, sex, age, and insulin use, the difference in A1C was 0.40% (95% CI 0.10-0.70, P = 0.009). Change in medication adherence measured by claims data, but not by self-report measures, was significantly associated with change in A1C (P = 0.01). Improvement in medication adherence was associated (P = 0.005) with the telephonic intervention, but only among those not taking insulin. No diabetes self-care activities were significantly correlated with the change in A1C.

Conclusions: A 1-year tailored telephonic intervention implemented by health educators was successful in significantly, albeit modestly, improving diabetes control compared with a print intervention in a low-income, insured, minority population.

Figure 1

Decline in A1C, expressed as median (interquartile range), per category of telephone intervention intensity (number of calls) compared with print group (no calls), estimated in a multiple linear regression model adjusting for baseline A1C, age, sex, insulin use, and improvement in MPR ≥20%.