The effect of history of injection drug use and alcoholism on HIV disease progression

Abstract

The effectiveness of highly active antiretroviral therapy (HAART) in preventing disease progression can be negatively influenced by the high prevalence of substance use among patients. Here, we quantify the effect of history of injection drug use and alcoholism on virologic and immunologic response to HAART. Clinical and survey data, collected at the start of HAART and at the interview date, were based on the study Longitudinal Investigations into Supportive and Ancillary Health Services (LISA) in British Columbia, Canada. Substance use was a three-level categorical variable, combining information on history of alcohol dependence and of injection drug use, defined as: no history of alcohol and injection drug use; history of alcohol or injection drug use; and history of both alcohol and injection drug use. Virologic response (pVL) was defined by ≥2 log₁₀ copy/mL drop in a viral load. Immunologic response was defined as an increase in CD4 cell count percent of ≥100%. We used cumulative logit modeling for ordinal responses to address our objective. Of the 537 HIV-infected patients, 112 (21%) were characterized as having a history of both alcohol and injection drug use, 173 (32%) were nonadherent (<95%), 196 (36%) had a CD4⁺/pVL⁺ (Best) response, 180 (34%) a CD4⁺/pVL⁻ or a CD4⁻ /pVL⁺ (Incomplete) response, and 161 (30%) a CD4⁻ /pVL⁻ (Worst) response. For individuals with history of both alcohol and injection drug use, the estimated probability of non-adherence was 0.61, and (0.15, 0.25, 0.60) of Best, Incomplete and Worse responses, respectively. Screening and detection of substance dependence will identify individuals at high-risk for nonadherence and ideally prevent their HIV disease from progressing to advanced stages where HIV disease can become difficult to manage.

Keywords:

• alcohol
• injection drug use
• adherence
• HAART
• HIV
• disease progression

Acknowledgments

This study was supported by capacity building and knowledge transfer grants from the Canadian Institutes of Health Research. Dr Lima was supported by a grant from the US National Institute on Drug Abuse [R03 DA033851-01] and by a Scholar Award from the Michael Institute for Health Research. Dr Montaner is supported by the Ministry of Health Services, Province of British Columbia, through a Knowledge Translation Award from the Canadian Institutes of Health Research and through an Avant-Garde Award [1DP1DA026182-01] from the National Institute on Drug Abuse, at the US National Institutes of Health. Dr Thomas Kerr has received grants from Canadian Institutes of Health Research [MOP-81171, HHP-67262, CIHR-251559, MOP-111039], US National Institutes of Health [R01 DA011591], and Foundation Open Society Institute [OSI-20030805]. Dr Kerr has also received support from Michael Smith Foundation for Health Research. Dr Evan Wood has received grants from Canadian Institutes of Health Research [MOP-102742, PHE-104125] and US National Institutes of Health (NIH) [R01 DA028532]. Dr Wood has also received support from Canada Research Chair program through a Tier 1 Canada Research Chair in Inner City Medicine. Dr Hogg has held grant funding in the last five years from the US National Institutes of Health, Medical Research Council UK and the Canadian Institutes of Health Research. The funding sources had no role in the choice of methods, the contents or form of this work, or the decision to submit the results for publication.

Supplemental Material

All Supplemental Material is available alongside this article on www.tandfonline.com - go to http://dx.doi.org/10.1080/09540121.2013.804900.