Self-monitoring leads to slightly better blood pressure control, review finds

Self-measurement of blood pressure improved management of hypertension in the first year after initiation, but long-term effects are uncertain, according to a recent systematic review.

Reviewers included in their meta-analysis 52 prospective studies that compared self-measured blood pressure (SMBP) monitoring with or without additional support (which included education, counseling or Web support, among other supportive interventions) to usual care or an alternative SMBP intervention. Results were published in Annals of Internal Medicine on Aug. 6.

In the 26 studies that compared SMBP with no support to usual care, moderate-strength evidence showed a benefit to the self-monitoring (difference in systolic and diastolic blood pressures, −3.9 mm Hg and −2.4 mm Hg, respectively). However, by 12 months, there was no difference between the groups. The 25 studies that included additional support for SMBP patients showed higher-strength evidence and a longer lasting effect (differences ranging from −3.4 to −8.9 mm Hg systolic and −1.9 to −4.4 mm Hg diastolic at 12 months).

However, the 13 studies that directly compared SMBP interventions with and without support provided low-strength evidence that the extra support made no difference, and in the overall analysis, there was insufficient evidence of the effect of SMBP on any clinical outcomes. Still, the review authors concluded that SMBP without additional support lowered blood pressure compared to usual care, at a magnitude that would be clinically relevant on a population level if it were sustained over time.

Given the lack of evidence about SMBP's effects beyond 12 months, and the limitations of the included studies (underpowering, different additional support interventions in every study), the authors called for additional research to resolve current uncertainty about the long-term clinical effectiveness of SMBP. In addition to lowering clinic-measured blood pressure, the intervention's potential benefits include tailoring treatment to patients' individual needs, potentially avoiding overtreatment as well as undertreatment, they noted.