TUESDAY, May 24, 2005 (HealthDay News) -- Within six months of starting medications to reduce their high blood pressure and lower cholesterol levels, one in three patients tracked in a new study failed to take those medications as prescribed, researchers report.
Patients with both high blood pressure and high cholesterol are at substantially greater risk of heart disease and cardiac events than people with either condition alone, the study authors noted.
Reporting in the May 23 issue of the Archives of Internal Medicine, researchers at ValueMedics Research, in Arlington, Va., analyzed a managed-care organization's database, identifying more than 8,400 patients who'd been prescribed both anti-hypertensive and cholesterol-lowering medications. They then tracked each patient's adherence to the drug regimens for an average of almost 13 months.
Three months after starting their treatment regimen, just 44.7 percent of patients were still adhering to it, with that number dropping to just under 36 percent at both the six-month and one-year mark.
At the same time, the researchers found that between 25.3 percent and 29.6 percent of patients were taking one drug properly as prescribed, but failing to adhere to instructions for the second drug.
The strongest predictor of adherence was the number of other prescriptions a patient was taking in the year before they began their blood pressure and cholesterol medications. As the overall number of prescribed drugs increased, the likelihood of adherence to these additional two medicines decreased, the researchers noted.
Older patients were also less likely to adhere to medications as prescribed compared with younger patients, and women were less compliant with doctor's instructions than men, the researchers added.
Finally, the time elapsed between starting blood pressure and cholesterol treatments seemed to be important, too. Patients who started taking the antihypertensive and cholesterol-lowering drugs on the same day or within a month of each other were 34 percent more likely to be adherent with both medicines during the three-year study period, compared with patients who started to take one drug two to three months after beginning the other.
Based on the findings, "physicians may be able to improve medication adherence substantially by reducing the number of [other] medications and by initiating antihypertensive and lipid-lowering medications together or close in time," the researchers wrote.
The American Medical Association has more information about coronary artery disease.