title: Factors associated with illicit opioid use in methadone maintenance treatment clients in 5 Provinces, China.
abstract: OBJECTIVE
  To investigate factors associated with illicit opioid use among methadone maintenance treatment (MMT) population.
  
  
  METHODS
  Participants were recruited from Beijing (2 clinics), Shanghai (2 clinics), Guangdong (2 clinics), Chongqing (2 clinics) and Gansu (1 clinic) provinces. Information about heroin use and MMT was obtained from a self-reported questionnaire, illicit opioid use was obtained from monthly medical records. Binary logistic regression was used to investigate factors associated with illicit opioid use.
  
  
  RESULTS
  Five hundred ninety-eight eligible MMT participants were used for data analysis. Variables such as age, gender, route of heroin use and daily MMT dosages were associated with illicit opioid use. Compared with MMT participants aged <40 years, participants aged 40-44 years (P = 0.027, OR = 0.57, 95 % CI 0.35-0.94), 45-49 years (P < 0.001, OR = 0.41, 95 % CI 0.24-0.67) and ≥50 years (P = 0.008, OR = 0.52, 95 % CI 0.33-0.85) were more likely not to have illicit opioid use. Compared with male participants, females were more likely to have illicit opioid use (P = 0.044, OR = 1.53, 95 % CI 1.01-2.32). Compared with inhalation heroin abusers, abusers with route of inhalation + injection heroin use were more likely to have illicit opioid use (P = 0.009, OR = 2.00, 95 % CI 1.19-3.36). Compared with daily MMT dosages <60 mg participants, participants with daily MMT dosages >80 mg were more likely to have illicit opioid use (P = 0.003, OR = 2.37, 95 % CI 1.35-4.15).
  
  
  CONCLUSIONS
  Age, gender, route of heroin use and daily MMT dosages were associated with illicit opioid use. A tailored intervention is needed for a promotion of MMT.
authors.affiliation: School of Public Health, Peking University, Beijing, 100191, China.|National Institute on Drug Dependence, Peking University, 38 Xueyuan Road Haidian District, Beijing, 100191, China.|Shandong Center for Disease Control and Prevention, Shandong, 250014, China.
authors.forename: Weixiu
authors.initials: W
authors.lastname: Li
authors.affiliation: School of Public Health, Guizhou Medical University, Gui'an New Area, 550025, China.
authors.forename: Ziyun
authors.initials: Z
authors.lastname: Wang
authors.affiliation: National Institute on Drug Dependence, Peking University, 38 Xueyuan Road Haidian District, Beijing, 100191, China. zhiminliu@bjmu.edu.cn.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000328:Adult; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008691:Methadone / Q000008:administration & dosage; D008875:Middle Aged; D058850:Opiate Substitution Treatment / Q000706:statistics & numerical data*; D009293:Opioid-Related Disorders / Q000453:epidemiology*; D057566:Self Report; D055815:Young Adult
chemical_list: D008691:Methadone
keywords: Heroin use; MMT; Methadone maintenance treatment; Risk factors; Urine morphine test