Are Automated Blood Pressure Monitors Comparable to Ambulatory Blood Pressure Monitors? A Systematic Review and Meta-analysis.

Ambulatory blood pressure (BP) monitoring (ABPM) provides an accurate assessment of BP and cardiovascular risk. BpTRU (BpTRU Medical Devices Ltd, Coquitlam, British Columbia, Canada) and other automated oscillometric BP monitors (AOBPs) have been proposed to replace ABPM. A systematic review was carried out to determine the accuracy of AOBP measurement, compared with ABPM. A literature search was performed using MedLine, EMBASE and CINAHL databases until Oct 28, 2016. We selected all studies that included intraindividual comparisons between AOBP monitoring and ABPM. Study selection, demographic characteristics, and BP values including details of BP measurement techniques were abstracted in duplicate. Quantitative synthesis was performed to report the weighted mean difference between systolic and diastolic BP measured using the 2 methods. From the 859 nonduplicate citations from the search, 19 full-text articles were selected for the systematic review. The median sample size was 226 (range, 17-654). In the pooled analysis, the weighted mean difference between the 2 methods for systolic BP was -1.52 mm Hg (95% confidence interval [CI], -3.29 to 0.25 mm Hg; P = 0.09) and for diastolic BP was 0.33 mm Hg (95% CI, -0.97 to 1.64; P = 0.62). The study-level difference in means for systolic BP ranged from -9.7 to 9 mm Hg with significant heterogeneity (Cochran Q = 270; I2 = 93.3; P < 0.001) and for diastolic BP ranged from -4 to 6 mm Hg with significant heterogeneity (Cochran Q = 382; I2 = 95.3; P < 0.001). Because of the significant heterogeneity we believe that use of the AOBP should not replace awake ambulatory BP (ABPM) as the reference standard.