Clinical Question

Is fully automated blood pressure measurement more accurate than manual sphygmomanometry?

Bottom Line

There are two takeaways and a recommendation from the analysis of in-office automated blood pressure measurement: automated measurement aligns better with ambulatory blood pressure monitoring, the best predictor of cardiovascular events, than manual measurement; manual readings are an average 13.4 to 14.5 mm Hg (systolic) higher than daytime ambulatory or automated readings in patients with hypertension; the recent guidelines from the American College of Cardiology/American Heart Association are based on automated readings. Follow them only if you switch from the squeeze bulb to the machine. (Level of Evidence = 1b)

Synopsis

The authors searched three databases, including the Cochrane Central Register of Controlled Trials, to identify studies that compared automated in-office blood pressure readings with standard or research-based manual measurement or ambulatory automated recording during awake hours (the latter used as the reference standard). The authors also searched reference lists of identified articles. Two authors independently selected articles for inclusion, and a single investigator extracted data. They included papers in any language. Automated measurement had to be performed without anyone activating the machine and used three to five readings separated by one- to two-minute intervals. In 31 studies of 9,279 participants, the pooled mean differences between routine measurement and awake ambulatory measurements were 13.4 mm Hg systolic and 5.9 mm Hg diastolic. There was no difference between ambulatory and automated blood pressure. The difference between manual and automated blood pressures was 14.5 mm Hg systolic in patients with hypertension. There was a great deal of heterogeneity among studies for all outcomes that could not be explained by any of the variables available to the researchers. There was no evidence of publication bias.

Study design: Meta-analysis (other)

Funding source: Self-funded or unfunded

Setting: Various (meta-analysis)

Reference: Roerecke M, Kaczorowski J, Myers MG. Comparing automated office blood pressure readings with other methods of blood pressure measurement for identifying patients with possible hypertension: a systematic review and meta-analysis. JAMA Intern Med. 2019;179(3):351–362.

Editor’s Note: Dr. Shaughnessy is an assistant medical editor for AFP.