Investigation of Repeat Client Drop-Out and Re-Enrolment Cycles in Fourteen Methadone Maintenance Treatment Clinics in Guangdong, China

Objective Client adherence is vital for effective methadone maintenance treatment (MMT). This study explores the pattern and associated factors of client adherence, drop-out and re-enrolment in the Chinese MMT programme over the period of 2006-2013. Methods This retrospective study was conducted in 14 MMT clinics in Guangdong Province, China. We employed Kaplan-Meier survival analysis to estimate the rates of drop-out and re-enrolment of MMT clients and multivariate Cox regression to identify associated factors. Results Among 1,512 study participants, 79% have experienced 'drop-out' during the 7-year study period. However, 82% 'dropped-out' clients resumed treatment at a later time. Low education level (junior high or below versus otherwise, HR = 1.21, 1.05-1.40), low methadone dosage in the first treatment episode (<50 ml versus >= 50 ml, HR = 1.84, 1.64-2.06) and higher proportion of positive urine test (>= 50% versus <50%, HR = 3.72, 3.30-4.20) during the first treatment episode were strong predictors of subsequent drop-outs of the participants. Among the 'dropped-out' clients, being female (HR = 1.40, 1.23-1.60), being married (HR = 1.19, 1.09-1.30), and having a higher proportion of positive urine tests in the first treatment episode (>= 50% versus <50%, HR = 1.35, 1.20-1.51) had greater likelihood of subsequent re-enrolment in MMT. Clients receiving lower methadone dosage (first treatment episode <50 ml versus >= 50 ml, HR = 1.12, 1.03-1.23; the last intake before drop-out <50 ml versus >= 50 ml, HR = 1.16, 1.04-1.30) were also more likely to re-enrol. Conclusion Persistent cycling in-and-out of clients in MMT programmes is common. Insufficient dosage and higher proportion of positive urine samples in the first treatment episode are the key determinants for subsequent client drop-out and re-enrolment. Interventions should target clients in their early stage of treatment to improve retention in the long term.