Treatment entry and return to opioid use outcomes from a pre-release methadone program in a Malaysian prison: towards improved HIV treatment outcomes

Abstract

Within prison, a high prevalence of people living with human immunodeficiency virus (HIV) and opioid use disorder exist. Return to opioid use is common among people released from incarceration. Regardless of incarceration length, an estimated 85% of individuals return to opioid use within one year. Return to opioid use is associated with significant harms. Methadone may reduce return to opioid use and benefit people living with HIV and opioid use disorder due to increasing antiretroviral therapy (ART) adherence, engagement with healthcare services and reducing the risk of HIV transmission. This thesis utilises data from Project Harapan, a pre-release methadone maintenance treatment (MMT) program conducted between 2010 and 2013 in Malaysia. The overarching aim of this thesis was to explore different aspects of the pre-release MMT program among a sample of 310 men living with HIV and opioid use disorder in Malaysia’s largest male prison. This thesis comprises four studies. The first study describes the association between knowledge and attitudes and the choice to initiate pre- release MMT. Uncertainty towards methadone may be associated with MMT-related hesitancy and lower proportions of men choosing to initiate pre-release MMT. The second study uses the behavioural model for vulnerable populations as a framework to explore the association between other factors connected to healthcare utilisation and the choice to initiate pre-release MMT. Findings suggest being of Hindu faith, being prescribed (yet not taking) ART, currently being on ART during incarceration and having a more severe craving for heroin were associated with lower proportions of men choosing to initiate pre-release MMT. The third study demonstrates the impact of pre- release MMT initiation on return to opioid use following release from incarceration. The findings reveal that reductions in opioid use in the first 12 months post-release may be associated with the initiation of pre-release MMT. With HIV-related mortality closely linked with people living with HIV and opioid use disorder, the fourth study reports on a global scoping review of HIV/AIDS, hepatitis and tuberculosis-related mortality among people who experience incarceration. Globally, it remains difficult to locate good-quality infectious disease-related mortality data for prisons. Given the paucity, we located data to suggest the highest number of reported deaths over a 20-year period were attributable to HIV/AIDS (n=3,305), followed by TB (n=2,892), HCV (n=189), HIV/TB co-infection (n=173) and HBV (n=9). Increased investment to improve the reporting of key mortality indicators is urgently required. This research resulted in one published manuscript, two accepted conference abstracts and three manuscripts awaiting submission post the conference embargo period. Thesis conclusions refer to men who experience incarceration in Malaysia in a study conducted between 2010 and 2013. Globally, evidence supports the effectiveness of pre-release MMT on reducing opioid-related harms yet given the paucity of such data among men living with HIV and opioid use disorder who experience incarceration in Malaysia, no such evidence existed, and the effectiveness remained unknown. Therefore, these findings make a significant contribution to the literature in relation to this previously hidden population. This thesis demonstrates that opioid-related harms can be reduced when individuals initiate pre-release MMT. Working towards optimising MMT uptake and supporting individuals to pursue effective treatment for opioid use disorder may prevent opioid-related harms and poor HIV treatment outcomes experienced by this vulnerable population