Am Fam Physician. 2021;104(2):116-117
Author disclosure: No relevant financial affiliations.
To the Editor: The U.S. Preventive Services Task Force (USPSTF) recommendation statement on hypertension in adults reaffirmed the benefits of screening1; however, it missed an opportunity to promote automated office blood pressure (AOBP) measurements as an easier-to-implement alternative to ambulatory blood pressure monitoring (ABPM). The guideline states that AOBP is comparable to ABPM; however, the supporting evidence review discounted the literature on AOBP by stating, “there is substantial heterogeneity and it is unclear if lack of mean mm Hg differences would result in similar diagnostic categorization and treatment decisions.”2 The most recent and largest meta-analysis found that this heterogeneity is not clinically significant.3
The Agency for Healthcare Research and Quality evidence synthesis states, “…without analysis of test accuracy outcomes (e.g., sensitivity, specificity), it is not possible to conclude whether AOBP would result in similar clinical screening and diagnostic results as ABPM or [home blood pressure monitoring].”4 This logic is flawed. If blood pressure is a continuous outcome related to cardiovascular risk, and AOBP is similar to ABPM, then it follows that the sensitivity and specificity of AOBP will be similar to that of ABPM. Mathematically, two measures cannot be so closely matched but have different sensitivities and specificities. The only difference will be for a threshold value for hypertension. For example, a person with an average systolic blood pressure of 140.2 mm Hg with one method could have a systolic blood pressure of 139.9 mm Hg with another method. However, there is no clinically significant difference in atherosclerotic cardiovascular disease risk between these two measurements. Multiple studies now recommend treating patients based on atherosclerotic cardiovascular disease risk5; therefore, the USPSTF should acknowledge the close correlation of AOBP and ABPM and recommend using the former.
Practicality also needs to be considered. It is logistically challenging to have patients submit multiple home blood pressure readings to diagnose hypertension. It is easier to implement a screening program with AOBP machines in the outpatient setting. Each clinic needs to purchase a device and screen each patient at the desired interval. If the USPSTF wants to optimize the detection of elevated blood pressure, it should recommend AOBP because it is easy to implement and closely resembles ABPM. The USPSTF cited only one randomized trial that reported improvements in clinically meaningful outcomes (i.e., hospitalization) from hypertension screening; this trial used AOBP for screening.6
Editor's Note: See related Putting Prevention into Practice: Screening for Hypertension in Adults