Approximately one-quarter of Americans have hypertension (high blood pressure). When left untreated, high blood pressure can lead to heart failure , aneurisms , kidney failure , heart attack , stroke , and vision loss. The good news about high blood pressure is that it can be effectively treated with lifestyle changes (i.e., exercise, diet changes, weight loss) and/or blood pressure-lowering medications.

A blood pressure test is usually part of a routine doctor’s visit. In patients with high blood pressure, physicians can use these tests to determine whether a person’s blood pressure treatment needs adjustment. Some researchers have proposed that in-home blood pressure monitoring may also help physicians make these decisions.

A new study in the February 25, 2004 issue of the Journal of the American Medical Association found that while making treatment decisions based on home versus office blood pressure measurement decreased medications and modestly lowered costs, it also resulted in slightly worse blood pressure control.

About the Study

This study included 400 men and women with high blood pressure who were taking no more than two blood pressure medications.

The researchers randomly assigned the participants to receive drug treatment based on either office or home blood pressure measurement. In the office-based group, blood pressure was based on the average of three consecutive readings taken by a physician. In the home-based group, blood pressure was based on the average of three consecutive self-measurements in the morning and in the evening over the course of a week. For in-home blood pressure monitoring, the participants used a digital manufacturer-calibrated device equipped with a printer.

Before the study began, after six months, and after one year, the participants underwent 24-hour ambulatory blood pressure monitoring, which involves wearing a small machine that takes blood pressure readings every 15-30 minutes. These readings were used to determine the effectiveness of blood pressure control in both groups.

Based on the home or office blood pressure readings, the physicians followed a standardized protocol to maintain, increase, or decrease drug treatment.

For one year, the researchers tracked each participant’s medication use, cost of treatment, and self-reported symptoms. In addition, they performed electrocardiography or echocardiography to measure the participants’ left ventricular mass (an indicator or heart complications from high blood pressure) after two months, six months, and one year.

The Findings

Both groups saw reductions in blood pressure, but these reductions were significantly greater in the office-based group. More participants in the home-based group than the office-based group, however, were able to permanently stop drug treatment (26% versus 11%, respectively).

There was no significant difference between the groups in terms of symptoms or left ventricular mass measurements after one year. Overall, the costs of the medications and follow-up visits were slightly lower in the home-based group.

How Does This Affect You?

These findings suggest that while relying on in-home blood pressure monitoring to guide treatment decisions may result in less medication and lower costs, it may also lead to less blood pressure control.

The study’s authors contend that managing high blood pressure exclusively with in-home blood pressure monitoring is probably not a good idea. However, they suggest that home measurement may be useful when used in conjunction with office measurement. Since significantly more participants in the home-based group were able to permanently stop drug treatment, it’s reasonable to conclude that many of these participants had white-coat hypertension—high blood pressure that occurs only in the physician’s office.

In-home blood pressure monitoring can help your doctor see how much your blood pressure changes during the day or if your blood pressure medication is working. And if you have white-coat hypertension, there’s a good chance in-home monitoring can detect it. To get an accurate reading, the American Academy of Family Physicians suggests you do the following before you measure your blood pressure:

  • Rest for 3-5 minutes without talking
  • Sit comfortably, with your legs and ankles uncrossed and your back supported
  • Sit still and place your arm on a table, level with your heart
  • Wrap the cuff around the upper part of your arm (snugly, but with enough room to slip one fingertip under the cuff)
  • Make sure the bottom edge of the cuff is one inch above the crease of your elbow