Comparison of blood pressure measurements on the bare arm, over a sleeve and over a rolled-up sleeve in the elderly.

Abstract

BACKGROUND: Although guidelines recommend that blood pressure (BP) should be measured on a bare arm, BP is sometimes measured over clothing in clinical settings. OBJECTIVE: To assess the accuracy of BP measurements over clothing rolled up to the elbow in clinical settings. METHODS: This was a cross-sectional study to a total of 186 individuals recruited from a primary care clinic and two day-care facilities between July and September 2014. Main outcome measures were BP measurements on (i) a bare arm, (ii) over the sleeve of a cardigan and (iii) over the sleeve of a cardigan rolled up to the elbow. BP was compared across measurement conditions using the paired t-test and multiple analysis of variance adjusting for age, sex, measurement order and interaction between clothing condition and measurement order. RESULTS: Of 186 subjects, 38.5% were male. Mean age was 74.6 years. Mean BP with a bare arm, over a sleeve and over a rolled-up sleeve was 128.9 (SD 19.1)/67.4 (10.8) mmHg, 132.8 (21.0)/72.6 (11.5) mmHg and 133.4 (21.3)/74.4 (12.1) mmHg, respectively. There were significant differences in BP between the bare arm and over a cardigan sleeve (P < 0.001) and the bare arm and over a rolled-up cardigan sleeve (P < 0.001). BP differences were significant even after adjusting for age group, sex, measurement order and interaction between clothing condition and measurement order. CONCLUSIONS: Although previous studies have suggested BP measurements over clothing are acceptable, our results suggest that BP should be measured on bare arms as recommended by guidelines whenever feasible.