People with high blood pressure who want to reduce their risk of having a stroke or dying prematurely should get their prescriptions filled and see their doctor regularly.

In a large study of Medicaid patients, researchers found that the more closely a person adhered to his or her doctor’s recommendations for filling their blood pressure medication prescription, the lower his or her risk of stroke and death.

Taking just one more pill as recommended each week (from a one-a-day regimen) cut stroke risk by 9 percent and death risk by 7 percent, Dr. James E. Bailey of the University of Tennessee Health Science Center in Memphis and colleagues report in the Journal of General Internal Medicine.

They looked at the medical records of about 49,000 Tennessee Medicaid patients for 1994 to 2000 to determine if blood pressure medication refill adherence or frequency of physician visits influenced risk of stroke or death. The researchers also investigated whether the type of blood pressure-lowering drugs a patient took was associated with stroke or risk of dying.

Patients were taking two different types of blood pressure drug on average, although some were taking as many as six. Sixty percent of the patients filled their prescriptions less than 80 percent of the time, and were classified as non-adherent to their medication.

During follow-up, which ranged from 3 to 7 years, 619 study participants had a stroke and 2,051 died.

Patients who were non-adherent were a half-percent more likely to die over a five-year period compared to adherent patients. Blood pressure drugs known as thiazide diuretics, ACE inhibitors, calcium channel blockers and beta blockers all cut death risk by 3 to 4 percent, while thiazide diuretics also cut stroke risk.

“This study demonstrates that medication adherence, a factor very amenable to change, is among the most important cardiovascular risk factors” for people with high blood pressure, Bailey and his colleagues note.

Based on the findings, they say, increasing US patients’ refill adherence to 80 percent or greater could save about 200,000 lives over the next five years.

Patients in the study averaged about five doctor office visits a year, although there was a wide range, with some not seeing a doctor at all and others logging nearly 90 visits a year.

Patients who visited the doctor more often were 1 percent less likely to die, even after the researchers took other illnesses into account, a finding they call “striking.”

While the benefit was small, the researchers note, this study is the first to their knowledge to give “clear evidence” that office visits are beneficial for patients with high blood pressure.

SOURCE: Journal of General Internal Medicine, online February 18, 2010.