BACKGROUND: At global, national, and local level, the need for ongoing, timely and cost efficient, comprehensive drug treatment monitoring, and evaluation systems have clearly been well recognized.

OBJECTIVES: To test the feasibility of linking laboratory data and client intake data and its usefulness for modeling retrospectively, for the first time, 5-year longitudinal drug treatment outcomes in an Irish opiate treatment setting.

METHODS: A multisite, retrospective, longitudinal cohort study was implemented to evaluate outcomes for opiate users based on 1.7 million routine urinalysis results collected from 4,518 individuals presenting for opioid substitution treatment in Ireland from January 2006 to December 2010.

RESULTS: Analysis of opiates, cocaine, benzodiazepine, and cannabis use at treatment intake, 6 months and at 1-5 year follow-ups revealed differences in urinalysis protocols; significant differences in age of first drug use between those using and not using opiates at 5 years; significant decreases in opiate use; increases in benzodiazepine use and significant increasing effects of concurrent cocaine and benzodiazepine use on the odds of using opiates. Time series analysis of weekly proportions opiate positive predicted 16% (95% confidence interval: 7%-25%) of clients would be opiate positive 5 years postinitial intake.

Conclusions/Importance:: Underutilized urinalysis data can be used to address the need for cost effective, efficient evidence of drug-treatment outcomes across time, place, and systems. Linking and matching the cross-sectional data across sites and times also revealed where improvements in electronic records could be made.