How do doctors know that patients are taking their medications faithfully? How can physicians help patients stay on lifesaving drugs?
In one of the most in-depth studies of its kind, UCLA researchers found that combining three measurement tools for estimating adherence to drug regimens including an electronic pill bottle cap that provides a dated record gives physicians and researchers a more accurate picture of how faithfully patients stay on their prescribed treatments than ever before.
The study, reported in the May 15 issue of the Annals of Internal Medicine, may help physicians and researchers develop new ways to measure medication adherence as well as to develop interventions to help people with HIV and other chronic diseases stay on treatment. Patient non-adherence costs the nation nearly $100 billion annually.
Researchers worked with 108 HIV-infected adults taking protease inhibitors and other highly potent drugs that suppress the HIV virus. Every month for a year, researchers compared three methods of measuring patient adherence to see which most accurately reflected how patients behaved.
The first two methods included asking patients how well they followed the treatment regimen and counting the number of pills remaining in patients medication bottles. The third method used a special pill bottle cap with a microchip that automatically recorded each time the bottle was opened.
Researchers found that combining all three methods together to generate a special composite adherence score proved more accurate than using each adherence measure by itself.
The study revealed that after taking antiretroviral drugs for six months, patients with undetectable levels of HIV were taking their medication as prescribed about 85 percent of the time. But those with detectable virus blood levels took their pills only about 66 percent of the time. Overall adherence for the full group was 76 percent.