The Genetics of Opioid Addiction Risk Evaluation Tool (GREAT) for Treatment Response in Methadone Patients

Background: Current tools such as the Maudsley Addiction Profile (MAP) exist to evaluate different facets of addiction severity, however these instruments have neither been designed for nor validated within patients on methadone maintenance treatment (MMT). Objectives: We aimed to provide a reliable tool to evaluate multiple domains of treatment response for patients on MMT. This tool can be applied easily with minimal time to patients, researchers and clinicians. Patients and Methods: We modified the MAP to address health and social outcomes specific to the MMT patient population. Construction of the new tool was accomplished using expert opinion and MAP scores from participants recruited for the Genetics of Opioid Addiction (GENOA) study. This modified scale known as the GENOA Risk Evaluation Tool (GREAT) was then applied to 21 MMT patients in a generalizability study (G-Study) to assess reliability and consistency. We performed a criterion validation of the GREAT to assess the predictive validity of GREAT substance use domain scores against urine toxicology screening for illicit opioids using multi-variable logistic regression analysis (n = 117). Results: Results showed excellent test-retest reliability for the GREAT (0.95) and its subscales (all ≥ 0.94). Results from the regression model showed the GREAT substance use score was a significant predictor for 3-month history of illicit opioid use (Odds Ratio [OR]: 1.16, 95% Confidence Interval 1.05, 1.29; P = 0.003). Conclusions: A modified tool to assess methadone treatment response serves to identify patients at high-risk for relapse at a minimal cost, as well as evaluate the relevant physical and psycho-social domains affecting opioid-dependent patients. The GREAT will serve as a useful adjunct to regular clinical assessments, allowing clinicians and researchers to properly assess opioid addiction patient’s response to MMT.