Primary Care Centers Use Outdated Hypertension Diagnostics

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Clinicians in primary care settings are not following evidence-based guidelines for making a new diagnosis of hypertension, according to results of a new survey presented at the virtual American Heart Association's (AHA) Hypertension 2020 Scientific Sessions.

While values for out-of-office blood pressure measurements, eg, obtained via 24-hour ambulatory (ABPM) and home blood pressure monitoring (HBPM) are recommended before making a new diagnosis of hypertension, the survey of 282 professionals across 10 primary care medical centers found that more than three-quarters (79%) of respondents believe that BP measured manually with a stethoscope and BP cuff is avery or highly accurate mode of assessment.

The survey was designed to assess provider knowledge, beliefs, and practices regarding current BP diagnostics. Questions were sent via email to 420 providers at 10 primary care practices within a single healthcare system. Of the 282 respondents there were:

• 102 medical assistants
• 28 licensed practical nurses
• 33 registered nurses
• 86 primary care physicians (physician)
• 33 advanced practitioners (AP)

The survey also found that:

• More than 96% of health care providers reported that they always or almost always relied on clinic blood pressure measurements in making a new diagnosis of hypertension

• However, 60% of physicians and APs would prefer using ABPM if available.

“We were surprised that blood pressure measurements taken manually with a cuff and stethoscope was the most trusted method, and most often utilized when making a new diagnosis of hypertension,” said Beverly Green, MD, MPH, lead author of the study, a family physician at Kaiser Permanente Washington, a senior investigator at Kaiser Permanente Washington Health Research Institute, and associate clinical professor at the University of Washington School of Medicine in an AHA press release.​

“Additionally, most physicians and advanced practitioners thought the threshold for high blood pressure for 24-hour ambulatory or home blood pressure monitoring was >140/90 mm Hg, which does not reflect the updated new ACC/AHA [issued in 2017] or prior hypertension guidelines.”

The USPSTF and the 2017American Heart Association/American College of Cardiology Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults both recommend out of office measurements via ABPM and HBPM before making a new diagnosis of hypertension.

Additional findings:

• Most providers did not believe that automated clinic BPs, home BP, or kiosk BP measurements were very or highly accurate.
• Responses were mixed regarding whether patients received home BP training and whether home BP monitors were checked for accuracy.
• Physician/APs reported varying schedules for home BP measurement with no schedule the most common response (37.3%), followed by 14 days (19.1%), and 7 days (10.9%).
• Almost all physicians/APs reported using a clinic BP threshold of 140/90 mmHg for making a new diagnosis of hypertension
• Very few physician/APs reported guideline concordant home or ABPM diagnostic thresholds, with 140/90 mmHg the most common response

The guidelines issued by the ACC/AHA in 2017 revised definitions for normal and elevated BP and indicate that BP of ≥130/80 mm Hg be considered stage 1 hypertension (sidebar).

Study authors do note that the current research began before the release of those guidelines and at that time, ≥140/90 mm Hg was the appropriate criteria.

While authors acknowledge small sample size as a study limitation, they note that responses from multiple locations help strenghten the sample.