| Individuals with a history of injection drug use account for 31% of AIDS cases in the United States and up to half of those treated in many urban settings. This dissertation comprises a series of epidemiologic studies on the relationship between drug use and HIV treatment outcomes in the Johns Hopkins Clinical Cohort, and the development and pilot assessment of an interventional strategy, directly administered antiretroviral therapy (DAART). First, in a cross-sectional analysis of 764 treatment-eligible HIV-infected participants who completed a confidential survey, we found that active drug users were less likely to have used combination antiretroviral therapy, had lower self-reported adherence, smaller decreases in HIV RNA levels, and smaller increases in CD4+ cell counts than non-drug users. Conversely, former drug users and non-drug users were quite similar in utilization of and adherence with therapy, and in measures of treatment effectiveness. Second, in a longitudinal analysis of 695 treatment-eligible participants, who completed at least two confidential surveys at 6-month intervals, transitions from non-use to use of drugs were associated with worsening utilization of antiretroviral therapy, virologic status, and immunologic status, compared to those who remained non-users in consecutive surveys. In contrast, transitions from use to non-use of drugs were associated with improvements in all HIV treatment outcomes, compared to those who remained users in consecutive surveys. Finally, 50 participants were enrolled in a pilot study of DAART in a methadone treatment facility, located near the Johns Hopkins HIV Clinic. In a non-randomized cohort comparison study, the proportion of DAART participants who achieved viral suppression at 6 months was significantly higher than the proportions achieving viral suppression in two frequency-matched randomly-selected comparison groups from the Johns Hopkins HIV Clinical Cohort: drug users currently in methadone treatment, and non-drug users. This research highlights the close temporal relationship between changes in drug user status and HIV treatment outcomes, and provides the rationale for the further development and assessment of treatment models that integrate HIV care and substance abuse treatment. |
