App-enabled device no better than standard device for self-measuring blood pressure

Enhancing self-monitoring of blood pressure (SMBP) with a smartphone application is not superior to standard SMBP for blood pressure reduction or patient satisfaction, a randomized clinical trial found.

Researchers randomized 2,101 patients with uncontrolled hypertension, a desire to lower their blood pressure, and a smartphone to either standard or enhanced self-monitoring. All patients used a self-monitoring device they received in the mail. Those assigned to the standard group received a device, instructional videos made by study staff, and links to online SMBP resources, while those assigned to the enhanced group received a device with similar instructions plus instructions and support to install an app on their smartphone and periodically sync their device with the smartphone app to transmit measurements. The app included reminders to measure blood pressure, measurement tracking, interpretation, annotation and visualization tools, and support for emailing an SMBP summary. In-person clinic measurements were used to measure changes in blood pressure from baseline. Enrollment and randomization occurred from Aug. 3, 2019, to Dec. 31, 2020.

Along with the mailed BP measuring device, patients received web-based educational materials and phone-based support as needed. However, clinicians did not intervene and the study did not provide SMBP measurements to clinicians. The primary outcome was reduction in systolic blood pressure between baseline and the most recent clinic visit extracted from electronic health records at six months. Results were published Aug. 15 by JAMA Internal Medicine.

The mean change in systolic blood pressure from baseline to six months was −10.8 mm Hg in the enhanced group versus −10.6 mm Hg in the standard group (adjusted difference, −0.19 mm Hg [95% CI, −1.83 to 1.44]; P=0.81). Most secondary outcomes did not differ between groups, except for documented attainment of blood pressure control below 140/90 mm Hg, which occurred in 32% of the enhanced group and 29% of the standard group (odds ratio, 1.15; 95% CI, 1.01 to 1.34). Most participants in both groups were very likely to recommend their SMBP device to a friend (70% vs. 69%).

The researchers concluded that enhanced SMBP offers no benefit over standard SMBP when delivered without additional co-interventions or support. “Enhanced SMBP does not provide any additional reduction in BP, and patients would not recommend an enhanced SMBP device to their peers more than a standard device,” they wrote. “Future research should continue to evaluate novel technologies, which may yet provide a scalable and affordable approach to achieving better population-level BP control.”