Primary Care Corner with Geoffrey Modest MD: USPSTF Guidelines on Blood Pressure Screening

By Dr. Geoffrey Modest

The USPSTF just came out with their final recommendations about screening for high blood pressure in adults (see doi:10.7326/M15-2223), an issue not addressed in JNC8 (Eighth Joint National Committee).

Recommendations:

The current recommendation, unlike the previous USPSTF ones, assessed the diagnostic accuracy of different blood pressure measurement protocols
Grade A recommendation was given to “screen for high blood pressure; obtain measurements outside of the clinical setting for diagnostic confirmation (my emphasis)”
Perform a risk assessment for developing hypertension: those at highest risk are those with high-normal blood pressure (130-139/85-89), those who are overweight or obese, and African-Americans
Screening tests: office BP measurement done by manual or automated sphygmomanometer. Make sure proper protocol is used: use the mean of 2 measurements when patient is seated, allow for >= 5 minutes between entry into the office and blood pressure measurement (my emphasis), use the right size cuff, place patient’s arm at the level of the right atrium. Multiple measurements are most predictive of high blood pressure. “ambulatory and home blood pressure monitoring can be used to confirm a diagnosis of hypertension after initial screening”
Screening interval: adults >40yo should be screened annually, those 18-39 with blood pressure <130/85 and no other risk factors can be rescreened every 3-5 years
Treatment and interventions: for nonblack patients, initially use thiazide diuretic, calcium-channel blocker, ACE-I or ARB. For black patients, use thiazide or calcium-channel blocker. Initial or add-on treatment for patients with chronic kidney disease consists of ACE-I or ARB (but not both)
Balance of benefits and harms: net benefit of screening is substantial

Several Points:

The main issue I see regularly and repeatedly with the diagnosis and treatment of hypertension, by far, is that we rely on the blood pressure readings right after the patient is brought into the examining room, whether done by a medical assistant, nurse, or provider. In my experience I find very dramatic differences when the patient sits for 5 minutes in a quiet room (i.e., there are huge discrepancies between my own measurement right away, which can be 30+mm Hg higher than when I recheck 5 minutes later, perhaps because the patient is deconditioned and is walking to the exam room, or they are anxious about the exam, etc…). I also reinforce to the patient that if home-based blood pressure monitoring (HBPM) is being done, I have the patient bring the cuff to my office to make sure it is accurate vs my manual measurement and I suggest that the patient should sit down and relax several minutes before checking their pressure (I also suggest that the patient wait quietly a few minutes if they go to a pharmacy to have the blood pressure checked).
“USPSTF found convincing evidence that ABPM is the best method for diagnosing hypertension” noting that 15-30% of patients diagnosed with hypertension have lower blood pressure outside the office — see first figure below. (Of note, the accuracy of office-based blood pressure measurements does increase by averaging many different measurements)
The evidence is less substantial for home-based monitoring but confirms that “HBPM may be acceptable”. So, ABPM is the “reference standard” and HBPM is “an alternative method of confirmation if ABPM is not available”. See the 3 figures below, which provide evidence for their recommendations regarding ABPM and HBPM
For treatment goals, the USPSTF states that a target of 150/90 be used for people >60yo, and a goal of 140mm systolic be used in those <60yo (similar to the JNC 8 recommendations), though they mention the new SPRINT trial but are withholding incorporating it until it is published (for the SPRINT trial, see https://stg-blogs.bmj.com/bmjebmspotlight/2015/09/28/primary-care-corner-with-geoffrey-modest-md-aggressive-blood-pressure-management/ )
BUT, though they embrace ABPM/HBPM (which I really support), there are several significant lacunae in their recommendations, from my perspective
Though ABPM/HBPM is an important diagnostic confirmation of hypertension, it is only useful in those patients with nearly normal blood pressures (i.e., the higher the office-based blood pressure, the less likely ABPM is helpful. i.e., no need to do an ABPM if someone comes into the office with 230/130….)
And, related to that, for some reason they delete the comment in their draft recommendations that there should be immediate treatment for some people (e.g. BP>180/110)
They do not even mention lifestyle changes in their treatment section, but jump right into meds
The treatment recommendations also do not even mention diabetics (seems like the treatment recommendations are really an afterthought to their primary task of screening, and are not very complete)
I will refer you again to the NICE recommendations from 2011, which are quite extensive and, i think, really very thoughtful
See prior blogs for a review of ambulatory blood pressure monitoring (ABPM) and the draft USPSTF recommendations from early this year, which includes some of the NICE guideline recommendations (https://stg-blogs.bmj.com/bmjebmspotlight/2015/01/15/primary-care-corner-with-geoffrey-modest-md-uspstf-recs-on-ambulatory-blood-pressure-monitoring/ ) and of the JNC8 recommendations (see https://stg-blogs.bmj.com/bmjebmspotlight/2013/12/22/primary-care-corner-with-dr-geoffrey-modest-jnc-hypertension-guidelines-simple-goals/ )