Dulce Digital: An mHealth SMS-Based Intervention Improves Glycemic Control in Hispanics With Type 2 Diabetes

Abstract

Objective: Type 2 diabetes is growing in epidemic proportions and disproportionately affects lower-income, diverse communities. Text messaging may provide one of the most rapid methods to overcome the "digital divide" to improve care.

Research design and methods: A randomized, nonblinded, parallel-groups clinical trial design allocated N = 126 low-income, Hispanic participants with poorly controlled type 2 diabetes to receive the Dulce Digital intervention or usual care (UC). Dulce Digital participants received up to three motivational, educational, and/or call-to-action text messages per day over 6 months. The primary outcome was HbA_1c; lipids, blood pressure, and BMI were secondary outcomes. Satisfaction and acceptability were evaluated via focus groups and self-report survey items.

Results: The majority of patients were middle-aged (mean age 48.43 years, SD 9.80), female (75%), born in Mexico (91%), and uninsured (75%) and reported less than a ninth-grade education level (73%) and mean baseline HbA_1c 9.5% (80 mmol/mol), SD 1.3, and fasting plasma glucose 187.17 mg/dL, SD 64.75. A statistically significant time-by-group interaction effect indicated that the Dulce Digital group achieved a significantly greater reduction in HbA_1c over time compared with UC (P = 0.03). No statistically significant effects were observed for secondary clinical indicators. The number of blood glucose values texted in by participants was a statistically significant predictor of month 6 HbA_1c (P < 0.05). Satisfaction and acceptability ratings for the Dulce Digital intervention were high.

Conclusions: Use of a simple, low-cost text messaging program was found to be highly acceptable in this sample of high-risk, Hispanic individuals with type 2 diabetes and resulted in greater improvement in glycemic control compared with UC.

Trial registration: ClinicalTrials.gov NCT01749176.

Figure 1

CONSORT flow diagram. appts, appointments.

Figure 2

A: HbA_1c means and 95% CIs for the Dulce Digital and UC groups at baseline, month 3, and month 6. B: Association between the number of blood glucose values texted in by participants with a change in HbA_1c level from baseline to month 6 in the Dulce Digital group. Values adjacent to error bars represent the mean number of texts for each quintile. Note: The texting variable was analyzed as a continuous variable but was binned into quintiles for graphical presentation. Although HbA_1c change is represented on the y-axis for ease of interpretation, the month 6 HbA_1c level was used as the outcome variable (with control for baseline HbA_1c level) in regression analyses. Because of the curvilinear appearance of this relationship, the texting predictor was also examined using a quadratic term; however, the quadratic variable was not statistically significant.