Photo Credit: Liudmila Chernetska

Commonly used arm positions (lap and side) for measuring BP can overestimate readings, according to a study published in JAMA Internal Medicine. Hairong Liu and colleagues conducted a crossover randomized clinical trial involving 133 adults aged 18 to 80 years in Baltimore to examine the effect of different arm positions on BP readings. Participants were randomly assigned to sets of triplicate BP measurements with the arm supported on a desk, supported on the lap, and unsupported at the side. The researchers took a fourth BP measurement with the arm supported on a desk to account for intrinsic BP variability. The lap and side positions yielded significantly higher BP readings than desk positions, with difference-in-differences of 3.9 and 4.0 mm Hg, respectively, in systolic and diastolic BP for the lap and 6.5 and 4.4 mm Hg, respectively, for the side. The subgroups generally showed consistent patterns. The researchers emphasized adherence to guideline-recommended arm positions while taking a patient’s BP.