Study: Improper arm positioning during blood pressure measurements can lead to hypertension overdiagnosis

Editor's Note

A recent randomized crossover trial conducted at Johns Hopkins University reveals that improper arm positioning during blood pressure measurements can lead to significant overestimation, potentially contributing to over-diagnosis of hypertension. The findings appeared in Jama Network October 7.

The study, which included 133 participants, compared readings in three arm positions: supported on a desk at heart level (the guideline-recommended method), resting on the lap, and unsupported at the side. Systolic blood pressure readings were elevated by an average of 3.9 mm Hg when arms were rested on the lap, and by 6.5 mm Hg when unsupported at the side. Diastolic blood pressure was similarly overestimated.

Based on these results, even minor deviations from recommended arm positioning can have clinically meaningful consequences, researchers write, noting that misclassification of hypertension is particularly concerning for those with pre-existing elevated blood pressure reading and other higher-risk groups.