Difference in blood pressure between arms might reflect peripheral vascular disease

EDITOR—I believe that McAlister and Straus underestimate the frequency and significance of a blood pressure difference between the arms.1 They quote 6% from the paper by Harrison et al, but this group reported a difference in 10/131 (that is, 7.6%) normotensive subjects for systolic or diastolic differences, 44/310 hypertensive patients (14%) for a systolic difference, and 31/310 hypertensive patients (10%) for a diastolic difference.2

I have reviewed the English language literature and identified 11 studies with comparable data on at least 100 subjects. These …