Adherence and related determinants on methadone maintenance treatment among heroin addicts in Dehong prefecture, Yunnan province

Objective To determine the adherence to and its determinants of methadone maintenance treatment （MMT） among heroin addicts in Dehong prefecture in Yunnan province from 2005 to 2009. Methods A dynamic cohort analysis was conducted with the time of treatment initiation as the time of cohort entry, to calculate the proportion of adhering to the treatment at different time points after initiation of the treatment, and to study the determinants of adherence.Results A total of 3758 had been treated. Among them, 95.8% were males, 75.8% aged between 20-39 years, 90.4% were peasants or unemployed, 57.0% were ethnic minorities, 35.0% were single and 55.5% were married with spouses, 43.9% were illiterate or educated at most primary school. The age of first using drugs averaged at 23.93 years. About 96.3% of the study subjects had used heroin and 21.7% were HIV-infected. The minimum time under MMT was less than 1 month and the maximum 61 months. The median methadone dose at first delivery was 25 ml, with the minimum 1 ml and the maximum 330 ml. By the end of the study or observation period, a total of 1798 patients had withdrawn from treatment and 1960 were still under treatment. The proportions of adherence to or still being under the treatment after 1,3,6,9, 12,24, 36,48 and 60 months treatment were 0.919,0.847,0.756, 0.690, 0.637, 0.519, 0.417, 0.360 and 0.321, respectively. Multiple regression analysis using Cox proportional hazard model indicated that withdraw from the methadone maintenance treatment was significantly associated with location of the treatment clinics, year of treatment initiation, marital status, HIV infection status, methadone dose of first delivery and the result of last urine test for heroin use. Conclusion MMT attendants in Dehong prefecture had a relatively high withdraw rate and low adherence rate. More efforts are needed to provide tailored counseling and education to MMT attendants, to provide family and community support, appropriate methadone dose at first delivery, and to better coordinate with local police department. Key words: Methadone maintenance treatment;  Adherence;  Withdraw;  Determinant