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30-minute office BP monitoring yields lower readings than routine procedures
Patients who underwent 30-minute office BP monitoring tests had test results that were considerably lower than routine BP tests and reduced overtreatment of white-coat hypertension, according to research published in Annals of Family Medicine.
According to researchers, a patient undergoes 30-minute BP monitoring by sitting alone and undisturbed while his or her BP is automatically recorded every 5 minutes for seven readings. The BP is then determined by the mean of the last six BP readings.
One of the study’s authors said patients will be willing to make the change.
“In the past, when we only had 24-hour ambulatory BP monitoring to offer in addition to routine office measurements, patients did refuse sometimes because they found the procedure too cumbersome. But in our experience, patients hardly ever refuse to cooperate with [30-minute office BP monitoring],” Michiel J. Bos, MD, PhD, Gezondheidscentrum Ommoord Briandplaats, the Netherlands, told Healio Family Medicine. “No patient wants to use medication that they do not really need, especially since wrongly indicated medication may cause serious side effects. Spending just half an hour extra in our office to prevent all this is a sacrifice that almost all patients are very much willing to make. In our office, patients can make an appointment for [30-minute office BP monitoring], at a time that suits them, so lack of time is no valid excuse.”
For their study, Bos and Sylvia Buis, MD, MPH, enrolled 201 patients from a primary care clinic who had underwent 30-minute office BP monitoring over a 6-month period and compared the results with the last routine BP reading. In addition, the patients’ physicians were asked why they ordered the 30-minute method, how they treated their patients, and how they would have treated their patients without it.
The researchers wrote that the mean diastolic 30-minute office BP was 11.6 mm Hg lower than the mean diastolic routine BP readings (95% CI, 10.2-13.1), and the mean systolic 30-minute office BP was 22.8 mm Hg lower than the mean systolic routine BP readings (95% CI, 19.8-26.1). In addition, considerable differences existed in patients with and without suspected white-coat hypertension between the two BP procedures, and differences were larger in individuals aged 70 years or older. Bos and Buis also wrote that based on routine BP procedures alone, physicians said they would have started or intensified medication therapy in 79.1% of the studied cases (95% CI, 73.6-84.6). But when the results of 30-minute office BP were available, physicians started or intensified medication therapy in 24.9% of cases (95% CI, 18.9-30.9).
“[30-minute office BP] yields lower [BP] readings than routine office BP in patients selected by their family physicians, even patients not suspected of having white-coat hypertension,” Bos and Buis wrote. “In our study, the use of [30-minute office BP monitoring] in this select patient population led to much less intensification of antihypertensive medications regimens. [30-minute office BP monitoring] is a promising method to reduce overtreatment of white-coat hypertension in primary health care.”
In a related editorial, Lee A. Green, MD, MPH, professor and chair of the department of family medicine, University of Alberta, Canada, said making the switch to 30-minute office BP will involve some challenges, such as rethinking treatment and diagnostic thresholds and changing office procedures. Speaking to that last point, he said the ends justify the means.
“For some practices that will be easy, but for some of us it will mean at least changing our routines, and sometimes even rearranging our offices. Getting it right will be a good use for our teams’ quality improvement skills,” Green wrote. “Because hypertension treatment matters so much to so many, we owe it to our patients to get it right.” – by Janel Miller
Disclosure: The researchers report no relevant financial disclosures.
Perspective
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This study reveals very promising results that have significant implications for practice. First, the logistics of 30-minute office BP monitoring are a marked improvement in convenience over daytime ambulatory BP monitoring. This makes it more appealing and likely to be completed by patients. Second, the findings led to more than 50% of participants not being initiated on or having increased intensity of medication to treat hypertension. This is a remarkable opportunity to decrease costs, patient anxiety from being labeled “hypertensive” and potential side effects from unnecessary medication. Third, it appears routine use of this approach would discover unsuspected affected patients not otherwise felt to have “white-coat hypertension.” As the authors acknowledge, additional study will help determine if avoidance of apparently unnecessary medication treatment results in better morbidity and mortality outcomes. Overall, this seems like a very appealing opportunity to adjust the diagnostic approach to ambulatory patients regarding BP status — a great improvement.