Comparison of mercury and aneroid blood pressure measurements in youth.

Abstract

Because of concerns about the safety and environmental impact of mercury, aneroid sphygmomanometers have replaced mercury-filled devices for blood pressure (BP) measurements. Despite this change, few studies have compared BP measurements between the 2 devices. The SEARCH for Diabetes in Youth Study conducted a comparison of aneroid and mercury devices among 193 youth with diabetes (48% boys, aged 12.9 ± 3.7 years; 89% type 1). Statistical analyses included estimating Pearson correlation coefficients, Bland-Altman plots, paired t tests, and fitting regression models, both overall and stratified by age (<10 vs ≥10-18 years). Mean mercury and aneroid systolic and diastolic BPs were highly correlated. For the entire group, there was no significant difference in mean systolic BP using the aneroid device, but there was a -1.53 ± 5.06 mm Hg difference in mean diastolic BP. When stratified by age, a lower diastolic BP (-1.78 ± 5.2 mm Hg) was seen in those ≥10 to 18 years using the aneroid device. No differences in systolic BP were observed, and there were no differences in BP by device in individuals <10 years. Regression analyses did not identify any explanatory variables. Although a small discrepancy between diastolic BP measurements from aneroid versus mercury devices exists, this variation is unlikely to be clinically significant, suggesting that either device could be used in research or clinical settings.