by Beverly B. Green, MD, MPH, a Group Health Physician and Group Health Research Institute (GHRI) associate investigator
As a longtime Group Health Physician and GHRI scientist, of course I knew that hypertension, sometimes called “the silent killer,” seldom has any symptoms, so it’s easy for patients (and providers) to put off doing something about it. But I was shocked to discover that I actually had the condition I’d been studying for many years.
I found out that I had hypertension while planning the Blood Pressure Checks to Improve Hypertension Diagnosis (BP-CHECK) study, which the Patient-Centered Outcomes Research Institute (PCORI) recently approved for funding. Our research team had bought a 24-hour ambulatory monitor to test on a few volunteers and ourselves. I was the first to try it. My blood pressure (BP) readings were really high, and I assumed something must be wrong with the monitor. My BP had always been normal (and often low) at clinic visits. I run three miles a day with my dog, am a pescetarian (vegetarian plus fish), and maintain a healthy weight. So it did not make sense to me.
From prior research on hypertension, I had a couple of home BP monitors at my house, so I started checking, and as is true for most people, my BP would vary a lot over the course of a day. Sometimes it was low, but more often it was high. So I went to my family doctor, Dr. Andrea Chun, at Group Health. The medical assistant took my BP, and it was normal: 120/80 mm Hg. The doctor rechecked it: a tad bit higher. She told me to check it more at home. I asked what she would do with my home BP numbers. She said she would look at them. I knew guidelines advise averaging several days of BPs, but she did not have an easy way or time to do this.
At home, I did more BP checks and averaged several days on my own. My BP varied but was overall high. Seeing this, I asked my doctor to order an official 24-hour ambulatory BP test. (This is not to be confused with Holter monitoring, which measures the heart’s rhythm over a day or two.) My doctor had ordered only one of these 24-hour ambulatory BP tests before. I had to go to a different clinic to get the monitor put on. I wore it for a day, with it checking my BP every 20 minutes during the day and every hour at night. During the day, I had to stop what I was doing when it started to check my BP (which was not always easy to do). I had to go back to the clinic the next day to return the monitor. They attached it to a computer, and it printed out my average BP during the day and night and overall—and how much my BP varied. The verdict? Hypertension (10 points above the cutoff). My average BP from using a home BP monitor was almost identical. My doctor ordered antihypertensive pills, and they were mailed to me. Now I take the pills and check my BP at home using a home BP monitor. I don’t have to go into a clinic to know that my BP is controlled.
The main way hypertension is diagnosed is from BP measurement in a clinic. The problem with this is that BP varies so much. It is normal for BP to rise with exercise and be lower in the evening than the morning. And BP can also rise at a medical office (“white coat hypertension”), because so many people are uncomfortable in that environment. (Obviously, unlike most people, I was comfortable in the clinic, having worked there and having lower blood pressure there.)
My research team thinks better alternatives exist for diagnosing hypertension than what is happening now in routine practice. That’s why we’re launching BP-CHECK. Like Group Health researchers, PCORI puts particular value on what matters most to patients. So as part of our proposal, we also asked patients what they want: They want to know their true BP, to help prevent strokes and heart attacks, which are more common with uncontrolled hypertension.
To diagnose hypertension better, we think when there is a question about high BP, it should be measured more often, and the U.S. Preventive Services Task Force agrees. Before a hypertension diagnosis is made, the Task Force, which makes national recommendations about disease screening, recommends 24-hour ambulatory BP monitor testing—or else home BP monitoring (using average BP). They also said more research is needed on kiosk BPs, as you see at drugstores, with some models being shown to be accurate. Kiosks might be a convenient third alternative, because not everyone has a home BP monitor and training is needed to use them properly.
BP-CHECK will compare the accuracy, comfort, and convenience of three potential ways to confirm a hypertension diagnosis—in clinic, at home, or at a kiosk—against the “gold standard”: 24-hour ambulatory BP monitoring, as I had done. We will enroll more than 500 Group Health patients aged 18–85 with high BP at their last clinic visit and at a screening visit.
You can read more about BP-CHECK here: PCORI approves Group Health for $2.8 million research funding award
Kaiser Permanente Washington Health Research Institute
Kaiser Permanente Washington
July 20, 2016—With Patient-Centered Outcomes Research Institute support, Dr. Beverly Green will test how best to confirm new hypertension cases.
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