Department of Family and Community Medicine, University of Missouri, Columbia patilso@health.missouri.edu
The authors reported no potential conflict of interest relevant to this article.
This project was supported by grant number R01HS023328 from the Agency for Healthcare Research and Quality. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Agency for Healthcare Research and Quality.
How does home BP monitoring stack up against clinic and ambulatory measurements for the Dx and management of hypertension? Find out in this review.
National Health and Nutrition Examination Survey (NHANES) data from 2011 to 2014 revealed that 29% of adults in the United States have hypertension.1 Prevalence increases with age, so that 7% of adults ages 18 to 39 years, 32% of adults ages 40 to 59, and 65% of adults ages ≥60 years have the disease.1 This national survey data also showed that 53% of those given the diagnosis had uncontrolled hypertension, and that control of hypertension did not change significantly from 2009 to 2014.1
Elevated blood pressure (BP) has been the leading risk factor for death related to cardiovascular disease globally for the last 3 decades.2 Yet in 2 nationally representative samples, only 1 in 6 patients with documented BP ≥140/90 mm Hg received treatment intensification with new medication during primary care visits.3 Uncertainty about the representativeness of any single clinic BP measurement is a prominent reason for health care providers not to intensify therapy.4
Confirming the Dx outside the office.The 2015 US Preventive Services Task Force (USPSTF) guidelines on screening for hypertension state that, for most patients, a diagnosis of hypertension should be confirmed with out-of-office BP monitoring before initiating treatment.5 The USPSTF states that ambulatory BP monitoring (ABPM) is accurate for hypertension diagnosis and monitoring, and that home BP monitoring (HBPM) is an acceptable alternative, based on good quality evidence.
Access to ABPM, however, is often limited. In a 2015 survey of primary care clinics, only 25% of the 123 clinics that completed the questionnaire reported having access to it.6 Conversely, HBPM is widely available and acceptable to most patients. A recent NHANES survey showed that 43.5% of patients who were aware of their hypertension diagnosis engaged in HBPM.7
So what, exactly, should the role of HBPM be in the management of patients with hypertension? The evidence-based answers to the 10 questions that follow provide useful insights.
1. Can HBPM be used to confirm a Dx of hypertension?
Yes (Strength of recommendation [SOR] C).
In reviewing the diagnostic accuracy of various methods to confirm the diagnosis of hypertension, the USPSTF identified ABPM as the most accurate, followed by HBPM, with clinic BP measurements bringing up the rear.5 In adults ≥18 years of age, the USPSTF recommends obtaining BP measurements outside of the clinical setting for diagnostic confirmation before starting treatment unless the patient’s BP is ≥180/110 mm Hg, there is evidence of end-organ damage, or the patient has a diagnosis of secondary hypertension.5 The USPSTF recommends HBPM as an acceptable alternative to ABPM based on 6 studies including a total of 1253 participants.8 The percentage of patients with elevated office BP confirmed by HBPM to have hypertension was 45% to 84% across these 6 studies.
Sixteen studies from another systematic review evaluated the diagnostic accuracy of HBPM while using ABPM as a reference.9 This review found that HBPM had high specificity and negative predictive value, but low sensitivity and positive predictive value. There was moderate diagnostic agreement between HBPM and ABPM, with kappa statistic values of 0.37 to 0.73 across all studies.9