Substance Use and Alcohol among Key Populations at risk for HIV: Novel Approaches in Intervention Development and Evaluation.

摘要

Substance use and alcohol can have negative health consequences among both HIV-positive and -negative individuals, and are associated with behaviors that facilitate HIV transmission and acquisition, particularly among key affected populations disproportionately impacted by HIV, including transgender women, men who have sex with men (MSM) and adults from sub-Saharan Africa. Although there is a large body of literature documenting the overlap between substance use, alcohol and HIV, many gaps remain in our understanding of these intertwined conditions. For example, the relationship between HIV infection and different classes and patterns of substance use and alcohol consumption remain understudied among transgender women. On the other hand, those relationships are well-characterized for non-dependent substance-using and alcohol-drinking MSM, yet there are no evidence-based behavioral interventions efficaciously shown to reduce substance use, alcohol and associated harm exclusively for this population. Furthermore, among treatment-naive HIV-positive individuals, there is limited longitudinal data characterizing the impact of anti-retroviral treatment (ART) initiation on alcohol consumption. The objective of this dissertation was to address these gaps in the literature and help elucidate the complex interplay between substance use, alcohol consumption and HIV with a special emphasis on key affected populations. The study populations and study designs in this dissertation include: 1) transgender women from San Francisco (n=314) from a Respondent Drive Sampling (RDS) study conducted in 2010; 2) HIV-negative, sexually-active, substance-using and alcohol-drinking MSM from San Francisco (n=326) from a randomized controlled trial (RCT) on the efficacy of a behavioral intervention, Personalized Cognitive Counseling (PCC), compared to rapid HIV testing to reduce HIV-related sexual risk behaviors conducted from 2009--2012; and 3) HIV-positive individuals from rural Uganda initiating ART (n=502) from a prospective cohort study followed from 2005--2011. The key findings of these studies are summarized below.;In the RDS study, transgender women who reported any methamphetamine use (AOR 3.02 (95%CI=1.51--6.02)), methamphetamine use before or during anal intercourse (AOR 3.27 (95%CI=1.58--6.77)), and at least weekly methamphetamine use (AOR 3.89 (95%CI=1.64--9.23)) had significantly greater odds of testing positive for HIV, compared to those who did not use methamphetamine. Consistent associations were observed in RDS-adjusted models using sampling weights that take into account the probability of being recruited into the study and similarities between network members (homophilly). This is the first study that has examined the relationship between alcohol and substance use, and HIV infection among transwomen in an RDS study, by substance class type and by frequency, using global and situational measures. This study observed that transgender women who tested positive for HIV significantly used more methamphetamine, in general, and in conjunction with sex.;In the PCC trial, compared to MSM who received rapid HIV testing only, MSM randomized to PCC were more likely to report abstaining from alcohol consumption (RR=0.93; 95%CI=0.89--0.97), marijuana use (RR=0.84; 95%CI=0.73--0.98), and erectile dysfunction drug use (EDD; RR=0.51; 95%CI=0.33--0.79) over the 6-month follow-up in generalized estimating equation (GEE) models. PCC was also associated with significant reductions in frequency of alcohol intoxication (OR=0.58; 95%CI=0.36--0.90) over follow-up in ordered logistic regression models. Furthermore, PCC was associated with significant reductions in number of unprotected anal intercourse events while under the influence of methamphetamine (RR=0.26; 95%CI=0.08--0.84). The addition of PCC to rapid HIV testing may have benefits in increasing abstinence from certain classes of substances previously associated with HIV risk, including alcohol and EDD; and reducing alcohol intoxication frequency and high-risk sexual behaviors concurrent with methamphetamine use. Of note, there was no evidence that PCC was efficacious in reducing the pre-specified primary sexual risk behavior outcomes in the overall sample of MSM in the trial. This is the first study to report significant reductions in alcohol and substance use associated with PCC.;In the cohort study with HIV-positive Ugandans, among the current drinkers, 90 (83.3%) reported first abstaining from alcohol for at least 90 days during follow-up. The majority (n=50) of those who abstained reported doing so by their 3-month visit. Additionally, 14 participants became abstinent by their 6-month visit and the 26 participants became abstinent by their 9-month visit or later. Among the 90 who abstained from alcohol for at least 90 days, 21 (23.3%) resumed drinking at some point during the course of the 6-year follow-up (4 relapsed at 6 month, 2 at 9 month, and 15 after 9 month visits). In the pooled logistic regression (PLR) analysis, alcohol abstinence was most likely to start immediately after ART initiation (AORs for 6 month versus 3 month visit: 0.25 [0.10--0.61]; 9 month visit or later versus 3 month visit: 0.04 [0.02--0.09]). This study found that a large majority of HIV-positive alcohol drinkers starting ART reported becoming and remaining abstinent from alcohol consumption. (Abstract shortened by UMI.).