Substance abuse and dependence have detrimental effects at both the individual and societal levels. Treatment for such problems has been shown to reduce the negative consequences and represents a worthwhile investment. However, rates of retention in substance abuse treatment varies widely. To date no investigation has examined treatment retention across the substance abuse treatment population in Ireland. This study aims to describe the characteristics of service users entering substance abuse treatment programmes in the Cork and Kerry region of Ireland, and to identify the significant factors associated with treatment retention.

The National Drug Treatment Reporting System (NDTRS) was used to identify those service users beginning their first treatment episode between January 1st 2008 and December 31st 2013. Logistic regression analysis was used to ascertain significant factors which lead to retention in substance abuse treatment. Models were developed and assessed for goodness of fit and discriminatory ability between binary outcomes using a range of metrics. An adequate and thorough procedure was followed for examining validity of results.

Results indicated that 47% of service users completed their treatment programme while 53% dropped out prematurely. Furthermore, it revealed factors that are related to treatment retention including treatment modality, frequency of substance use, education level, living status, secondary substance used and the involvement of a concerned family member in the treatment episode. Additionally it was highlighted that the factors leading to treatment retention were the same for those using alcohol or illicit substances, with the exception of higher levels of secondary substance use among illicit substance users. Significant differences were also identified between those entering residential treatment compared to other forms of treatment.

Results are compared and contrasted with the existing substance abuse treatment literature. Study limitations are discussed, along with implications for service providers. Future investigations at the individual programme level are recommended to guide the monitoring, design, implementation, and evaluation of treatment procedures to enhance substance abuse treatment retention.