By Ed Susman, Contributing Writer, MedPage Today
Published: September 11, 2012
Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine, Harvard Medical School, Boston and Dorothy Caputo, MA, BSN, RN, Nurse Planner
SAN FRANCISCO – Single-pill regimens that simplify HIV treatment were of no help in getting people who don't take medication to start, researchers said here.
About 10% of patients prescribed a single-pill regimen did not fill those prescriptions, Cal Cohen, MD, of the Community Research Initiative of New England, in Boston, reported at the Interscience Conference on Antimicrobial Agents and Chemotherapy.
"What I found striking about these results," Cohen told MedPage Today, "was when patients were prescribed single-pill regimens there was no difference in the percentage of patients who were completely non-adherent."
About 8% of patients prescribed a non-nucleoside reverse transcriptase inhibitor-based regimen didn't fill those prescriptions; 12% of patients with boosted protease inhibitor-based regimens and 10% of those with an integrase inhibitor-based regimens didn't fill those prescriptions, according to Cohen.
The differences were not statistically significant, he said.
Doctors have believed that as HIV regimens become easier to use – such as a once-daily, single-pill regimens – the adherence levels would improve, said Cohen, who is also with Harvard Medical School/ Brigham and Women's Hospital in Boston. But in this study that compared non-adherent and partially adherent patients, there was no progress in the completely non-adherent group.
Cohen and colleagues retrospectively examined the LifeLink database of pharmacy and medical claims, identifying patients with an HIV diagnosis between January 2009 and the end of 2011 who received complete antiretroviral prescriptions. Adherence was reported as the percent of time with a complete regimen, a partial regimen and no antiretroviral medication. Refill data were used to analyze compliance.
The researchers found that 1,751 patients were assigned single tablet regimens; 522 were on regimens that included raltegravir; 1,601 patients were prescribed regimens containing a boosted protease inhibitor; and 675 were on a non-nucleoside reverse transcriptase inhibitor-based regimen.
The group also found that patients who were partially adherent – they took some drugs as prescribed and others randomly or not at all for periods that lasted as long as a month – ended up being hospitalized more frequently when compared with people who were prescribed single-tablet regimens. The partially adherent patients also ended up hospitalized 43% to 54% more often than the completely non-adherent patients.
For example, completely non-adherent single-tablet-regimen patients were hospitalized about 10.2% of the time, compared with 14.6% of those on the raltegravir-based therapy who took part of their regimen some of the time (P<0.0001). However, Cohen said that one of the limitations of the study is that patients were not randomized to one treatment or the other, allowing for unmeasured confounding to exist.
Cohen said the database didn't specify if the patients were hospitalized for HIV/AIDS-related illness. But he said his study suggests that single-pill regimens would eliminate hospitalizations among patients who were partially adherent, so he recommended using the simplified regimens.
In commenting on the study, Dan Bowers, MD, adult HIV and primary care provider at the Callen-Lourde Community Health Center Clinic, New York City, told MedPage Today, "I am not surprised at these results. There [is] a certain percentage of patients who just will not take their medications. It is not just limited to HIV patients. Some patients with any form of chronic disease will not take medication. There is a certain level that is beyond breakthrough."
The study was supported by Gilead Sciences.
Cohen has disclosed commercial interests with Bristol-Myers Squibb, Janssen Pharmaceuticals, Merck & Co.; and ViiV Healthcare. Bowers had no disclosures.
Primary source: Interscience Conference on Antimicrobial Agents and Chemotherapy
Cohen C et al, "H-211 - Association between selective adherence to antiretroviral therapy and hospitalization risk in an HIV population" ICAAC 2012.