<b>Objective:</b> Text
messaging interventions have high potential for scalability and to reduce health
disparities; however, more rigorous, long-term trials are needed. We examined
the long-term efficacy and mechanisms of a tailored text messaging intervention.
<p><b>Research Design and Methods:</b> Adults
with type 2 diabetes participated in a parallel-groups, 15-month randomized
trial, assigned to receive REACH (Rapid Education/Encouragement and
Communications for Health) for 12 months or control. REACH included interactive
texts and tailored texts addressing medication adherence, and non-tailored
texts supporting other self-care behaviors. Outcomes included HbA1c, diabetes
medication adherence, self-care, and self-efficacy. </p>
<p><b>Results:</b> Participants (N=506)
were approximately half racial/ethnic minority and half were underinsured, had
annual household incomes <$35,000 USD and ≤ high school education; 11% were
homeless. <a>Average baseline HbA1c was 8.6%±1.8%; 70.0±19.7 mmol/mol) with n<i>=</i>219
having HbA1c≥8.5% (69 mmol/mol)</a> and half were prescribed insulin. Retention
was over 90%. Median response rate to interactive texts was 91% (interquartile
range 75%, 97%). The treatment effect on HbA1c at 6 months (-0.31%; 95% CI
[-0.61%, -0.02%]) was greater among those with baseline HbA1c≥8.5% (-0.74%; 95%
CI [-1.26%, -0.23%]), and there was not evidence of effect modification by race/ethnicity
or socioeconomic disadvantage. REACH
improved medication adherence and diet through 12 months, and self-efficacy
through 6 months. Treatment effects were not significant for any outcome at 15
months. REACH reduced barriers to adherence, but barrier reduction did not
mediate outcome improvements. </p>
<p><b>Conclusions:</b> REACH
engaged at-risk patients in diabetes self-management and improved short-term
HbA1c. More than texts alone may be needed to sustain effects. </p>
Impact of Health Literacy, Self-efficacy, and Outcome Expectations on Adherence to Self-care Behaviors in Iranians with Type 2 Diabetes
