Impact of Ambulatory Blood Pressure Monitoring on Reclassification of Hypertension Prevalence and Control in Older People in Spain

Abstract

Ambulatory blood pressure monitoring (ABPM) accurately classifies blood pressure (BP) status but its impact on the prevalence and control of hypertension is little known. The authors conducted a cross-sectional study in 2012 among 1047 individuals 60 years and older from the follow-up of a population cohort in Spain. Three casual BP measurements and 24-hour ABPM were performed under standardized conditions. Approximately 68.8% patients were hypertensive based on casual BP (≥140/90 mm Hg or current BP medication use) and 62.1% based on 24-hour ABPM (≥130/80 mm Hg or current BP medication use) (P=.009). The proportion of patients with treatment-eligible hypertension who met BP goals increased from 37.4% based on the casual BP target to 54.1% based on the 24-hour BP target (absolute difference, 16.7%; P<.01). These results were consistent across alternative BP thresholds. Therefore, compared with casual BP, 24-hour ABPM led to a reduction in the proportion of older patients recommended for hypertension treatment and a substantial increase in the proportion of those with hypertension control.

© 2015 Wiley Periodicals, Inc.

Figures

Figure 1

Distribution of casual, 24‐hour, and daytime systolic blood pressure (SBP).

Figure 2

Scatterplots (panels a and b) and Bland‐Altman plots (panels c and d) for the association between casual and ambulatory systolic blood pressure (SBP). In panels a and b, solid circles represent treated patients and unfilled circles represent untreated patients. In panels c and d, the solid line indicates the mean SBP difference and dashed lines indicate the 95% limits of agreement (two standard deviations around the mean difference).

Figure 3

Number of patients eligible for medication treatment and percentage of patients with treatment‐eligible hypertension with blood pressure (BP) at goal, according to casual and 24‐hour BP. Medication‐eligible hypertension is defined as receiving treatment or above goal for each casual BP and 24‐hour BP target. Bars indicate 95% confidence intervals for percentage estimates of BP at goal; casual BP at goal, <140/90 mm Hg; 24‐hour BP at goal, <130/80 mm Hg.