Comparative assessment of four blood pressure measurement methods in hypertensives

Abstract

Introduction: Discordance between blood pressure (BP) measurement methods can occur and create ambiguity. New automated office BP monitors (AOBPs) are widely available, but their role is presently unclear. The objectives of this study are to quantify concordance among BP measurement methods and to define the diagnostic sensitivity, specificity, and predictive value of AOBPs in a population of hypertensive patients.

Methods: The office mercury sphygmomanometer, the AOBP, an ambulatory BP monitor (ABPM), and home self-measurement with an automatic device were compared in a randomized, crossover study. BP averages and achievement of therapeutic goals were defined. Comparisons and agreement tests were performed. Diagnostic indices were calculated for the AOBP.

Results: A total of 101 patients were enrolled. Average BP results were similar between measurement methods with the exception of daytime ABPM, which was significantly higher; figures are mean ± standard deviation (SD): sphygmomanometer, 129.9 ± 13.7/80.9 ± 9.3 mm Hg; AOBP, 128.4 ± 13.9/80.0 ± 9.4 mm Hg; 24-hour ABPM, 131.4 ± 11.7/78.7 ± 9.7 mm Hg; day ABPM, 135.5 ± 11.4/82.0 ± 11.9 mm Hg; home self-measurement, 131.0 ± 14.3/82.5 ± 8.2 mm Hg. Discordance in the achievement of therapeutic goals was observed in 58 patients, with only 26 cases being explained by masked hypertension or "white coat syndrome" according to all measurements. Disagreement was greater when office methods were compared with ambulatory methods.

Conclusions: This study shows that the 4 measurement strategies provide similar average BP estimates but generate many discordant results. The AOBP device can be very valuable as a replacement for the sphygmomanometer.