Doctors already recommend that people with high blood pressure use a home monitor. But research suggests that home readings only make a small difference in getting the condition under control.

Dr. Karen Margolis, executive director of research at the HealthPartners Institute in Minneapolis, and her colleagues tested a “telemonitoring” program designed to give patients more help. Their home readings were sent electronically to a pharmacist within the health system who then had regular phone “visits” with the patients.

Over the next 18 months, compared with patients on standard care, those in the telemonitoring program lowered their blood pressure by an extra 7 to 10 points on average, the study found. And over five years, they were half as likely to suffer a heart attack or stroke, or develop heart failure.

Dr. Tracy Stevens, a cardiologist and volunteer expert with the American Heart Association, agreed. “This cries out for larger studies,” she said.

But the broader message, according to Dr. Stevens, is that home monitoring is critical. “A blood pressure measurement taken in the doctor’s office may not reflect what’s going on in our daily lives,” she said. “We want to treat the home blood pressure,” she said, “not the office blood pressure.”