Letters to the Editor
To the Editor:
Dr. Beber et al state that the evidence presented in our paper concerning the association of alcohol consumption and HIV disease progression “is not strong enough to completely support this point of view.” They cite concerns regarding the assessment of alcohol consumption and antiretroviral therapy (ART) adherence. We used well-validated measures for both.1,2
The main finding of our analyses was that among those HIV-infected individuals who were not currently on ART, there was a significant association between heavy alcohol consumption and lower CD4 cell count (adjusted mean decrease of 48.6 cells/μL compared with those who were abstinent). Concerns regarding ART adherence measurement could not affect this main finding in people not taking ART. The 30-day measurement period for alcohol consumption repeated every 6 months may not accurately reflect alcohol use during the entire 6-month interval. It also does not reflect the lifetime of drinking that may have occurred in the individual. Despite the possibility that the assessment may have underestimated lifetime or even recent exposure to alcohol, possibly resulting in decreased power to detect an effect on HIV disease progression, we detected an association. Furthermore, we used appropriate analytic techniques to account for changes over time (linear mixed- effects models with time-varying covariates for alcohol consumption).
We do agree that our findings may not be generalizable to HIV-infected patients who have never had alcohol problems; we also cannot be certain that the observed association represents cause and effect. Nonetheless, our data strongly suggest that heavy drinking can have a modest adverse effect on HIV disease progression beyond that generally attributable to alcohol's impact on adherence to HIV medications.
Jeffrey H. Samet, MD, MA, MPH*†
Debbie M. Cheng, ScD*‡
Richard Saitz, MD, MPH*§
*Clinical Addiction Research and Education Unit, Section of General Internal Medicine, Department of Medicine, Boston Medical Center, Boston University School of Medicine, Boston, MA
†Department of Social and Behavioral Sciences;
§Epidemiology and Youth Alcohol Prevention Center, Boston University School of Public Health, Boston, MA.
1. Sobell L, Sobell M. Alcohol Timeline Followback (TLFB) Users' Manual
. Toronto, Canada: Addiction Research Foundation; 1995.
2. Chesney MA, Ickovics JR, Chambers DB, et al. Self-reported adherence to antiretroviral medications among participants in HIV clinical trials: the AACTG adherence instruments. Patient Care Committee & Adherence Working Group of the Outcomes Committee of the Adult AIDS Clinical Trials Group (AACTG). AIDS Care