Retention And Its Associated Factors Among Clients Of The Eight Pilot Methadone Maintenance Treatment Clinics In China: A Prospective Cohort Study

Retention and Its Associated Factors among Clients of the Eight Pilot Methadone Maintenance Treatment Clinics in China:a Prospective Cohort StudyBackgroundWhen China commenced its methadone maintenance treatment (MMT) program in 2004, there were no prior studies identifying the barriers and facilitators for clients' retention under China's unique social and cultural context. A better understanding of subject's therapeutic dynamics and factors associated with them is crucial to examine the treatment effect and identify ways to improve the program.ObjectivesThe primary aim of this study was to describe the subjects'overall treatment dynamics and identify major factors associated with subjects'retention over the six-year period among the first eight MMT clinics in China.MethodsA prospective cohort study was conducted among 1511 clients who enrolled in the eight pilot MMT clinics in China in 2004. The clients were followed-up between March 23,2004 and June 30,2010. Data were collected using 1) Baseline standardized structured interview,2) China's Methadone Information Management System,3) MMT clinic medical records, and 4) on-site follow-up.Descriptive methods were used to describe the overall picture of subjects' treatment dynamics. Chi-square tests, Kaplan-Meier, and Cox PH regression models were used to investigate factors associated with retention and death. All references were made on the basis of a two-tailedα=0.05 level.Results1. By the end of June 2010,35.7% of the 1511 subjects remained in treatment, 54.1% dropped out and 10.2% died during the six-year follow-up period.2. Over the six-year follow-up period, the average treatment time span was 42.8 months, and the actual length of taking methadone was 25.3 months. The average daily dosage was 48.6 mg/day. There was gap between treatment span and actual length of taking methadone.3. Characteristics of treatment dynamics over six-year follow-up included:1) the number of subjects remained in treatment and retention rate decreased overtime,2) subjects were most likely to drop out of treatment during the first 1-1.5 years after the start of treatment,3) re-entering was prevalent among those who dropped out.4. During the six-year follow-up period, over half (57.9%) of subjects had two or more treatment episodes. Respectively 49.7% and 8.2% of the subjects had 2-4 episodes and more than four episodes. The main cause of dropout were being arrested or sent to mandatory detoxification centers (48.7%), emigration/being out of town for work (10.5%) and self-withdrawn (10.3%).5. A total of 154 deaths were observed during the six-year follow-up period. The overall mortality rate was 29.5/1,000 person years. Most death cases happened during 2007-2008, accounting for 40.3% of all death cases. The leading cause of death was overdose (33.8%), followed by non-AIDS diseases (21.4%) and AIDS (16.9%). Male subjects had nearly two times higher mortality rates than that of females (31.0/1000 vs 16.8/1,000 person years).6. Daily dosage higher than 60mg/day, having taken methadone for more than 3 years, and having family members receiving MMT predicted the lower risk of dropout and the lower risk of death during the follow-up, whereas frequent contact with current drug users increased the risk of death.ConclusionsSpecial attention should be paid to subjects who entered treatment within 1-1.5 years. The result highlights the needs to evaluate clients'individual characteristics and provide tailored intervention and services. It is suggested to increase treatment dosage, extend actual length of taking methadone and reduce concurrent illicit drug use for the MMT clients in China.