In a new study, people with high blood pressure who could communicate with their pharmacists online had better blood pressure control a year after that service ended.

Previously researchers had found that patients randomly assigned to the web-based pharmacy care did better than those who used a patient website but had no extra help or were only trained to monitor their blood pressure at home.

The new findings suggest some of those benefits may hold up over the long run – even after patients stop messaging with their pharmacists, researchers said.

Hayden Bosworth, who studies treatment adherence at Duke University Medical

Center in Durham, North Carolina, said there’s been a lot of interest in how to help patients stick more closely to their blood pressure and cholesterol medications, for example.

“From a health care plan perspective, these interventions are expensive and we need to look more at the sustainability of the effects and look at it long term,” said Bosworth, who wasn’t involved in the new research.

“We need to look at it from a (return on investment) perspective.”

The new study took place at Group Health, a Seattle-based health care system. Patients there already had online access to parts of their medical records and could email with their doctors through a secure website.

Researchers led by Dr. Beverly Green randomly assigned 778 people in the system with high blood pressure to one of three groups.

One group received usual care, a second was trained in how to monitor blood pressure at home and a third received the monitoring instruction and was able to communicate online with pharmacists.

A year after the intervention ended, 618 patients remained in the study. Blood pressure was controlled – meaning less than 140/90 milliliters of mercury (mm/Hg) – for 60 percent of people who had online access to pharmacists, compared to 48 to 52 percent of those in the other groups.

Average systolic blood pressure – the top number – was 134 in the pharmacy group versus 138 among usual care participants and 141 for the blood pressure monitoring only group. There was no difference between groups when it came to diastolic blood pressure, the study team reported in JAMA Internal Medicine.