Opioid substitution treatment (OST) to reduce HIV and risk behaviour

Opioid substitution treatment (OST) was found to be effective in systematic reviews (Mattick et al., 2009; Gowing et al., 2008, WHO, 2009) in:

• reducing the risk of HIV infection by approximately 54 % (RR 0.46, 95 % CI 0.32 to 0.67; 15 studies, N=819 incident HIV cases);
• reducing the frequency of injection, the sharing of injecting equipment and injecting risk behaviour scores:
  • injecting behaviour: prevalence of injecting :
    • one observational study (N=255) (RR 0.87, 95 % CI 0.80 to 0.95);
    • one RCT (N=253) (RR 0.45, 95 % CI 0.35 to 0.59)
  • Injecting behaviour: proportion of patients sharing injecting equipment:
    • three observational studies (N=1321) (RR 0.54, 95 % CI 0.37 to 0.79)
• reducing the risk of unsafe sex:
  • commercial sex:
    • one observational study (follow up to 18 months) (N= 257) (RR 0.62, 95 % CI 0.45 to 0.86);
    • two observational studies (follow up 3-6 months) (N= 867) (RR 0.94, 95 % CI 0.87 to 1.02)