Abstract: Objective Methadone maintenance treatment has been considered to be the best practice in the treatment for opiate dependence.It has been agreed by the researchers that treatment retention,employment status,and reduced criminal activity are the essential outcome variables for the treatment.The objective of the study was to recognize factors influencing outcomes of methadone maintenance treatment when patients initially attending the treatment program.Methods Participants were chosen from patients in five methadone maintenance treatment clinics in Xi'an City,Shanxi Province.Patients who had been in the clinic for less than one month were interviewed.There were two interviews in the study.The first one happened when the study began.Patients were asked about the addiction status one month before being recruited into the treatment.The second interview was done in the same population at a time when the participants had been in the treatment clinic for three months.Addiction status in recent one month was investigated in the second interview.Two hundred and eighty-two patients were followed for the two interviews.The Chinese version of Addiction Severity Index was used to evaluate the addiction status of the participants.The Chinese version of Addiction Severity Index was developed on base of the fifth version of the original one and has been proved to be valid and reliable.Unitary linear regression and single variable logistic regression was used when doing simple analysis and multiple linear regression model and multiple logistic regression model were used when doing the comprehensive analysis.Dependent variables included Length of stay in the treatment(actual days of receiving methadone during the first three months in the treatment);decline of times of illegal activities(comparison of times of illegal activities between one month before treatment and three months after treatment);whether having a job(employment status after three months' treatment).Independent variables were seven composite scores of the Chinese version of Addiction Severity Index,that were scores in seven area-medical status,employment status,alcohol abuse,drug abuse,legal status,family/social relationship and psychiatric status;demographic characteristics of the interviewees(age,gender and education level).Results Similar results were found in the unitary regression model and the multiple regression model.Most of the ten independent variables couldn't be included into the model.Age and composite score(psychiatric area) were included in the multiple linear regression with the significant level of 0.10. The Standardized coefficients were0.179(P=0.002) and0.111(P=0.059),respectively.Only gender entered the multiple logistic regression with the dependentvariable of 'decline of times of illegal activities'.The odd ratio was 0.131(95%Confidence Level was 0.024～0.710).Composite score(employment area) and composite score(legal area) were of statistical significance in the multiple logistic regression model with the dependent variable 'whether having a job'.The odd ratio was 0.035(95%Confidence Level was 0.009～0.139)and 0.018(95%Confidence Level was 0.065～0.517),respectively.Patients with young age or severe problems existed in any of the three area: psychiatric area,employment area and legal area were related with negative treatment outcomes.Conclusion Age,composite score(psychiatric area),composite score(employment area) and composite score(legal area) were the factors influencing outcomes of methadone maintenance treatment.Staffs in the clinics should recognize the patients with these characteristics in their early time of coming to the clinic and make proper treatment plan and additional intervention to increase the outcome of the treatment.

Key words: outcomes of methadone maintenance treatment, factors, addiction severity index