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

Lei Zhang, Xia Zou, Di Zhang, Xiaoling Li, Peizhen Zhao, Li Ling

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Client adherence is vital for effective methadone maintenance treatment (MMT). This studyexplores the pattern and associated factors of client adherence, drop-out and re-enrolmentin the Chinese MMT programme over the period of 2006–2013.


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-enrolmentof MMT clients and multivariate Cox regression to identify associated factors.


Among 1,512 study participants, 79% have experienced ‘drop-out’ during the 7-year studyperiod. However, 82% ‘dropped-out’ clients resumed treatment at a later time. Low educationlevel (junior high or below versus otherwise, HR = 1.21, 1.05–1.40), low methadonedosage in the first treatment episode (<50 ml versus 50 ml, HR = 1.84, 1.64–2.06) andhigher proportion of positive urine test (50% versus<50%, HR = 3.72, 3.30–4.20) duringthe 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 firsttreatment episode (50% versus<50%, HR = 1.35, 1.20–1.51) had greater likelihood ofsubsequent re-enrolment in MMT. Clients receiving lower methadone dosage (first treatmentepisode <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.


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.
Original languageEnglish
Article numbere0139942
Number of pages13
JournalPLoS ONE
Issue number10
Publication statusPublished - 2015
Externally publishedYes

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