Effect of Opioid Agonist Treatment on Survival and Cessation among Patients with Injection Drug

Few studies have reported the long-term effectiveness of opioid agonist treatment (OAT) on injection drug use (IDU) cessation and survival. Between 1980–2007, Edinburgh Addiction Cohort researchers identified 794 patients with a history of IDU and flagged them for follow-up with the UK National Registry Office. Between 2005–2007, 432 of the patients were interviewed regarding early life experience, substance use, and health and social histories. In addition, data were extracted from medical and death-registration records for 655 patients.

• Among interviewees, 135 (31%) were currently using injection drugs; of these, 83% were also receiving OAT.

• Among patients followed up via medical records, 558 (85%) received OAT at some point during the follow-up period. Of these, 277 achieved long-term cessation (at least 5 consecutive years of no IDU), and 228 died. The leading causes of death were HIV infection (45%), drug overdose (24%), and liver disease (11%).

• In adjusted analyses, each additional year of OAT decreased risk of death before long-term cessation by 13%.

• Among patients who did not receive OAT, probability analysis indicated that 25% would be dead within 25 years of first injection compared with 6% of patients who received at least 5 years of OAT.

• Opiate agonist treatment was inversely associated with long-term IDU cessation.

Comments:

This study showed a cumulative survival benefit among patients receiving OAT but also showed that OAT does not reduce, and may even increase, the overall duration of IDU. The benefits on survival applied to patients with evidence of continuing IDU as well; therefore, withdrawing these patients from treatment programs would negatively impact their survival. These results support a risk-reduction approach to OAT that retains patients with continuing use.

Nicolas Bertholet, MD, MSc

Reference:

Kimber J, Copeland L, Hickman M, et al. Survival and cessation in injecting drug users: prospective observational study of outcomes and effect of opiate substitution treatment. BMJ. July 1, 2010 (E-pub ahead of print).