A National Study of the Retention of Irish Opiate Users in Methadone Substitution Treatment

Abstract

Background: Retention in treatment is a key indicator of methadone treatment success. The study aims to identify factors that are associated with retention. Objectives: To determine retention in treatment at 12 months for Irish opiate users in methadone substitution treatment and to indicate factors that increase the likelihood of retention. Methods: National cohort study of randomly selected opiate users commencing methadone treatment in 1999, 2001, and 2003 (n ¼ 1269). Results: Sixty-one percent of patients attending methadone treatment remained in continuous treatment for more than 1 year. Retention in treatment at 12 months was associated with age, gender, facility type, and methadone dose. Age and gender were no longer significant when adjusted for other variables in the model. Those who attended a specialist site were twice as likely to leave methadone treatment within 12 months compared with those who attended a primary care physician. The most important predictor of retention in treatment was methadone dose. Those who received <60 mg of methadone were three times more likely to leave treatment. Conclusion: Retention in methadone treatment is high in Ireland in a variety of settings. The main factors influencing retention in methadone treatment was an adequate methadone dose and access to a range of treatment settings including from primary care physicians. Scientific Significance: Providing an adequate dose of methadone during treatment will increase the likelihood of treatment retention. Methadone treatment by the primary care physician is a successful method of retaining opioid users in treatment.

Demographic and clinical factors predicting retention in methadone maintenance: results from an Irish cohort

“…A retrospective cohort study of over forty thousand individuals prescribed opioid replacement therapy between 1985 and 2006 in Australia found that age had the biggest impact on risk of leaving treatment with older respondents having a lower prevalence of breaks in treatment [23]. This finding was replicated in similar large cohort studies in Switzerland, Shanghai, America and Ireland [21,22,25,31]. These studies focused primarily on breaks in treatment in last 12 months, while our research asked patients whether they ever had a break in treatment at any time.…”

“…Gender predicted retention in some previous studies [31] but not in others [13]. Findings generally favour females having a higher retention rate [22]. For example, a literature review of 19 studies on retention in MMT and predicting factors in China between 2004 and 2012 reported females having a higher retention rate than males [24].…”

“…Some of the main patient characteristics that predict retention are female gender [20,[22][23][24], older age ([30 years) [20,21,23,24,25], stable living conditions [21], good health [13], high level of education [24,25], being married, increased psychological stability, intact social support networks, employment [20,24] and minimal criminal history [13,20]. A number of factors associated with drugs have been linked with retention such as prior treatment experience [21], shorter and milder drug abuse history, older age of first drug use, less frequency of drug use, not injecting drugs and minimal contact with other drug users [20,24,25].…”

“…A number of factors associated with drugs have been linked with retention such as prior treatment experience [21], shorter and milder drug abuse history, older age of first drug use, less frequency of drug use, not injecting drugs and minimal contact with other drug users [20,24,25]. Programme factors include a higher methadone dose generally above 60 mg a day [13,22,[24][25][26][27][28][29], greater treatment satisfaction [13,27], primary care treatment setting [22,23] and counselling support [13].…”

“…The primary reasons for exiting treatment included incarceration and programme-related factors such as disagreeing with programme rules, conflict with staff and schedule conflicts [30]. Previous research in an Irish MMT setting has acknowledged the need for more research on the type of factors which contribute most to retention, treatment satisfaction and the reasons why patients take breaks from treatment [2,22]. This study will aim to address these gaps in knowledge working to identify demographic and clinical factors associated with retention in treatment in a cohort of opiate-dependent methadone-maintained patients receiving treatment in Ireland.…”