BackgroundHypertension is an important risk factor for cardiovascular outcomes. Primary
health care (PHC) physicians should be prepared to act appropriately in the
prevention of cardiovascular risk factors. However, the rates of patients
with control of blood pressure (BP) remain low. The impact of the
reclassification of high BP by 24-hour ambulatory BP monitoring (ABPM) can
lead to different medical decisions in PHC.ObjectiveTo evaluate the agreement between the BP measured by a conventional method by
PHC physicians and by 24-hour ABPM, considering different BP normal
thresholds for the 24-hour ABPM according to the V Brazilian ABPM Guidelines
and the European Society of Hypertension Guidelines.MethodsA cross-sectional study including 569 hypertensive patients. The BP was
initially measured by the PHC physicians and, later, by 24-hour ABPM. The BP
measurements were obtained independently between the two methods. The
therapeutic targets for the conventional BP followed the guidelines by the
Eighth Joint National Committee (JNC 8), the V ABPM Brazilian Guidelines,
and the 2013 European Hypertension Guidelines.ResultsThere was an accuracy of 54.8% (95% confidence interval [95%CI] 0.51 - 0.58%)
for the BP measured with the conventional method when compared with the
24-hour ABPM, with a sensitivity of 85% (95%CI 80.8 - 88.6%), specificity of
31.9% (95%CI 28.7 - 34.7%), and kappa value of 0.155, when considering the
European Hypertension Guidelines. When using more stringent thresholds to
characterize the BP as "normal" by ABPM, the accuracy was 45% (95%CI 0.41 -
0.47%) for conventional measurement when compared with 24-hour ABPM, with a
sensitivity of 86.7% (95%CI 0.81 - 0.91%), specificity of 29% (95%CI 0.26 -
0.30%), and kappa value of 0.103.ConclusionThe BP measurements obtained by PHC physicians showed low accuracy when
compared with those obtained by 24-hour ABPM, regardless of the threshold
set by the different guidelines.