Correlates of methadone client retention: A prospective cohort study in Guizhou province, China

Background: Methadone client retention levels and treatment doses of patients vary widely in methadone clinics across China. Because methadone clinics have been available in China only recently, this study explored the relationship between methadone dosage and client retention in methadone maintenance programmes in Guizhou province. Methods: The study used a prospective cohort study design. Injecting and non-injecting heroin-using clients who had been treated for no more than two and half months in one of eight methadone maintenance treatment clinics in Guizhou province were recruited into the cohort, beginning on 3 June 2006 and followed up until 1 June 2007. A total of 1003 participants were enrolled. Face-to-face interviews were conducted to collect baseline information, and clients' daily doses were recorded. Results: The 14-month retention rate was 56.2%. Controlling for other covariates in the multivariate Cox model, a higher methadone dose was found to predict higher client retention. Retention was also associated with intention to remain in treatment for life and the clinic attended. Conclusion: Clients need to receive an adequate methadone dose to assure continued retention. Patients who expect to be treated for life have higher retention rates than patients who anticipate only short-term treatment. Key factors associated with successful clinics in China need to be elucidated.