Use of Short Messaging Service for Hypertension Management: A Systematic Review.

Only 6 studies met inclusion criteria, so the review could not answer which SMS format works best. The meta-analysis was not completed because the studies varied too much: I2 was 93.5% for systolic BP and 89.9% for diastolic BP. Five studies had high risk of bias and one unclear risk; all 6 had selection bias, and only 2 used random assignment. Only 3 studies had 80% statistical power; the other 3 did not report power or had unknown power. SMS content, frequency, duration, and whether it was the main or supplemental component varied widely, so the effect of SMS alone could not be isolated. Sample sizes were limited and samples were predominantly white, so generalizability is narrow. No study reported cost effectiveness, so feasibility in usual care is unclear.

Do not conclude that text messaging lowers blood pressure. The review included only 6 studies, 3 reported improved BP and 3 reported no significant BP, and SMS was often combined with education, coaching, or provider feedback, so the effect of SMS alone cannot be separated.