Skip Navigation Archive: U.S. Department of Health and Human Services U.S. Department of Health and Human Services
Archive: Agency for Healthcare Research Quality
Archival print banner

This information is for reference purposes only. It was current when produced and may now be outdated. Archive material is no longer maintained, and some links may not work. Persons with disabilities having difficulty accessing this information should contact us at: Let us know the nature of the problem, the Web address of what you want, and your contact information.

Please go to for current information.

  • Publication # 13-RA008

Dosing frequency has greater impact than pill burden on medication adherence by patients with newly diagnosed HIV

Chronic Disease

Patients with conditions such as HIV disease that require either taking medication more than once a day or taking multiple medications may find it difficult to adhere to their medication regimens. For patients recently diagnosed with HIV, once-daily dosing of a combination antiretroviral therapy (cART) medication resulted in higher adherence than twice-daily dosing. However, among patients on a once-daily regimen, adherence to a one-pill regimen was no different than adherence to regimens with more than one pill. The results suggest that pill burden is not an important factor in determining adherence to once-daily cART regimens in patients who begin taking cART, suggesting that other factors should drive regimen selection.

Data on the effects of the cART regimen on HIV suppression compared to other regimens was inconclusive due to the small size of the study. The 99 patients in the study were all recently diagnosed with HIV infection and being treated at a clinic in Houston, Texas. This study was supported in part by AHRQ (HS16093). 

See “Impact of antiretroviral dosing frequency and pill burden on adherence among newly diagnosed, antiretroviral-naïve HIV patients,” by A. Buscher, M.D., C. Hartman, Ph.D., M.A. Kallen, Ph.D., and T.P. Giordano, M.D. in the International Journal of STD & AIDS 23, pp. 351-355, 2012.


Page last reviewed May 2013
Internet Citation: Dosing frequency has greater impact than pill burden on medication adherence by patients with newly diagnosed HIV: Chronic Disease. May 2013. Agency for Healthcare Research and Quality, Rockville, MD.


The information on this page is archived and provided for reference purposes only.


AHRQ Advancing Excellence in Health Care