Weekly automated phone calls can help people with hypertension control their blood pressure more effectively, Canadian researchers have shown.

After about a year, 46 percent of men and women who got such calls had brought their blood pressure down to optimum levels, compared to about 29 percent of people who didn’t receive calls, Dr. Pavel Hamet of the University of Montreal and his colleagues report.

“A fairly simple intervention supported by technology that consumed very little human resources can be highly effective in primary care settings,” they write in the journal Circulation: Cardiovascular Quality and Outcomes.

Just one in four North Americans with hypertension have their blood pressure under control, Hamet and his team note, and part of the reason may have to do with “inadequate management” by doctors and poor communication from health care providers.

To get information flowing more effectively, the researchers designed a computer-based management program to call people and ask them for their most recent home-recorded blood pressure measurement. The system combined this data with information on medication refills and then faxed monthly reports to doctors, pharmacists and nurses.

Hamet and his colleagues randomly assigned 223 people with high blood pressure to receive an educational booklet, a digital blood pressure monitor, and a log for keeping track of their blood pressure readings and adherence to medications, or to get the educational booklet only.

People given the monitors and logs also got an automated phone call each week that collected their blood pressure and adherence information and received personal calls from nurses if they weren’t taking their prescribed medication or didn’t have their blood pressure under control.

All of the study participants were followed for at least five months, with follow-up averaging just under a year. Nurses made 209 calls to study participants after getting E-mail alerts on poor blood pressure control or non-adherence.

By the end of the study, people in the phone call group were taking two drugs for high blood pressure, on average, compared to one drug for the control group.

Systolic pressure, the top number in a blood pressure reading, showed an average 18.7-point reduction in the study group, compared to 13.8 points for the control group. Diastolic pressure, the lower reading, fell 9.1 and 5.6 points, respectively.

The systolic blood pressure reduction, the researchers pointed out, would reduce stroke risk by up to 35 percent, and heart attack risk by up to 25 percent, if it was sustained.

“It appears the intervention achieved its success by providing regular inter-visit feedback to primary care professionals, decreasing clinical inertia as well as regular contact and feedback to the subjects, empowering them to take charge of their disease,” Hamet and his colleagues conclude.

SOURCE: Circulation: Cardiovascular Quality and Outcomes, online May 5, 2009.

Larkin, K. T., and Zayfert, C.
Published with assistance from the foundation established in memory of Amasa Stone Mather of the Class of 1907, Yale College.