Attended Automated Office Blood Pressure Measurement Versus Ambulatory Blood Pressure Monitoring in a Primary Healthcare Setting in Chile

Objectives As part of the HEARTS in the Americas initiative, Chilean primary healthcare centers have implemented novel hypertension management strategies, including new diagnostic approaches. This study evaluated the concordance between attended automated office blood pressure (AOBP) measurements with an oscillometric device and ambulatory blood pressure monitoring (ABPM). Methods This was an observational cohort study to evaluate and compare attended AOBP and ABPM for the diagnosis of hypertension in adults in a primary healthcare setting. Results The study evaluated 309 participants (54.2 +/- 15.7 years; 50.5% male) from four primary healthcare centers in Santiago, Chile. Attended AOBP measurements were obtained at the clinic on two separate days, followed by ABPM. AOBP values indicated that 69.6% of patients had a systolic blood pressure (SBP) of >= 140 mm Hg and 34.6% had a diastolic blood pressure (DBP) of >= 90 mm Hg. A total of 83.5% had hypertension, 45.3% had high SBP, and 56.0% had high DBP. ABPM values indicated that 65.0% of patients had hypertension. The combined AOBP and ABPM analysis showed that 57.0% of patients had sustained hypertension, 26.5% had white coat hypertension, 8.1% had masked hypertension, and 8.4% were normotensive. The concordance between AOBP and ABPM (kappa coefficient) was low (kappa = 0.133; 95% confidence interval 0.028-0.237). The comparison of AOBP and ABPM measurements (Bland-Altman plots and bias calculations) showed an important bias in BP as measured using the AOBP method, especially for SBP (13.7 +/- 11.6, 95% confidence interval -9.1 to 36.5). Conclusions Attended AOBP alone may not be sufficient for adequate classification, diagnosis, and management of hypertension in Chile or other countries with similar demographics.