Text Message Adherence Support for High Blood Pressure

Study Questions:

Can automated treatment adherence support delivered via mobile-phone text message improve blood pressure control?

Methods:

This was a single-blind, three-arm randomized trial conducted in South Africa. Participants were patients treated for high blood pressure, with enrollment between June 2012 and November 2012. Participants were randomized in a 1:1:1 ratio to either information-only or interactive short message system (SMS) text-messaging; with a third group receiving usual care. The primary outcome was change in systolic blood pressure at 12 months from baseline. Intention-to-treat analysis was used.

Results:

A total of 1,372 participants were randomized to the three arms; information-only SMS text messages, (n = 457); interactive SMS test messages (n = 458); and usual care (n = 457). Mean (standard deviation) age was 54.3 (±11.5) years, >50% of participants were black, and 28% had at least 10 years of hypertension. Over one-half of the patients had a body mass index of at least 30 kg/m2. Other baseline characteristics were similar across the three groups. Nearly all the participants owned their own phone. Primary outcome data were available for 1,256 (92%) participants. At 12 months, the mean adjusted change (95% confidence interval [CI]) in systolic blood pressure compared to usual care was -2.2 mm Hg (95% CI, -4.4 to -0.04) with information-only SMS and -1.6 mm Hg (95% CI, -3.7 to 0.6) with interactive SMS. Odds ratios (95% CI) for the proportion of participants with a blood pressure <140/90 mm Hg were: for information-only messaging, 1.42 (95% CI, 1.03-1.95); and for interactive messaging, 1.41 (95% CI, 1.02-1.95), compared to usual care.

Conclusions:

The investigators concluded that an automated adherence support program delivered by SMS text message in a general outpatient population of adults with high blood pressure, resulted in a a small reduction in systolic blood pressure control compared to usual care at 12 months. However, there was no evidence that an interactive intervention increased this effect.

Perspective:

Although this trial did not observe large improvements in blood pressure, it should be noted that among a real-world population, which included those with a range of socioeconomic levels, this intervention was feasible with a significant reduction in systolic blood pressure compared to usual care. Further refinement of the text-messaging intervention, grounded on sound behavioral therapy, may improve the impact of this intervention. Thus, eHealth interventions may be a component of global public health interventions to improve blood pressure.

Keywords: Behavior Therapy, Blood Pressure, Blood Pressure Determination, Cell Phone, Early Medical Intervention, Hypertension, Metabolic Syndrome, Primary Prevention, Telemedicine, Text Messaging


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