Objectives: 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.
Keywords: Heroin use; MMT; Methadone maintenance treatment; Risk factors; Urine morphine test.