Barriers and facilitators to methadone maintenance therapy use among illicit opiate injection drug users in Vancouver

Abstract

Methadone maintenance therapy (MMT) has been increasingly implemented as the treatment of choice for opiate-addicted individuals and has been associated with reduced harm related to opiate addiction. Barriers to MMT uptake still exist, however, and many opiate-addicted individuals do not access this form of treatment. We examined barriers to and facilitators of MMT access among opiate users enrolled in a prospective cohort study of injection drug users (IDUs). We identified individuals who had initiated MMT during follow-up interviews and used generalized estimating equations to identify sociodemographic and drug-related variables associated with MMT access. Of the 1,587 participants recruited into the Vancouver Injection Drug User Study, 1,463 individuals were eligible for the present analysis. Factors negatively associated with MMT use included male gender (odds ratio [OR] = 0.41; 95 percent confidence interval [CI], 0.32 to 0.52), Aboriginal ethnicity (OR = 0.37; 95 percent CI, 0.29 to 0.48), recent incarceration (OR = 0.82; 95 percent CI, 0.72 to 0.93), Downtown Eastside residence (OR = 0.86; 95 percent CI, 0.75 to 0.97), sex-trade involvement (OR = 0.80; 95 percent CI, 0.67 to 0.95), syringe lending (OR = 0.76; 95 percent CI, 0.66 to 0.89), denied addiction treatment (OR = 0.81; 95 percent CI, 0.68 to 0.96), heroin injection (OR = 0.51; 95 percent CI, 0.44 to 0.59), nonfatal overdose (OR = 0.59; 95 percent CI, 0.51 to 0.68), and infecting in public (OR = 0.75; 95 percent CI, 0.63 to 0.89). Older age (OR = 1.03; 95 percent CI, 1.01 to 1.04), human immunodeficiency virus (HJV) positivity (OR = 1.89; 95 percent CI, 1.52 to 2.2.3), and crack cocaine smoking (OR = 1.41; 95 percent CI, 1.22 to 1.62) were positively associated with MMT use. Our study identified a large number of barriers to and facilitators of MMT use among IDUs. While some populations such as HIV-positive individuals are frequently accessing MMT, identified barriers among men and Aboriginal lDUs are of great concern. These findings indicate the need for additional interventions aimed at maximizing coverage of MMT and other treatments for opiate-addicted individuals.