Retention and its predictors among methadone maintenance treatment clients in China: A six-year cohort study

Abstract

BackgroundTo investigate factors associated with retention among the first cohort of drug users attending methadone maintenance treatment (MMT) clinics in China. MethodsA six-year cohort of 1511 drug users was enrolled in the first 8 MMT clinics in China in 2004 and followed between March, 2004 and December, 2010. Six-year retention rates were calculated and compared by methadone dosage, clinic location, and length of follow-up. Factors associated with retention were evaluated using Cox proportional hazard regression models. ResultsThe overall retention rate over 6-year was 35.7%. Highest drop-out occurred within the first 12 months of treatment. The retention rates for the 6-year by low (≤30mg/day), medium (31–60mg/day), and high (>60mg/day) methadone dosage groups were 20.8%, 34.8% and 53.2%, respectively (p<0.001). The highest 6-year retention rate among eight clinics was 43.8%, while the lowest one was 17.7% (p<0.001). The results from Cox proportional hazard models indicate that clients having >30mg daily methadone dosage (p<0.001), having relatives receiving MMT (p=0.027), and having >10% urine morphine positive result (p<0.001) were more likely to be retained in MMT over the six-year period. It has also found that drug injection (p=0.005) and needle sharing (p<0.0001) were significantly associated with better retention. ConclusionsHealth workers should adjust individuals’ methadone dosages as a method to prevent early treatment termination. Further studies are needed to explore the impact of severity of opiate addiction on long-term retention of MMT clients. Careful assessment of drug users upon MMT enrollment may be helpful for providing additional care to clients.