Comparison of the Concurrent and Predictive Validity of Three Measures of Readiness to Change Marijuana Use in a Clinical Sample of Adolescents

Abstract

The measurement of readiness to change has become common practice in alcohol and drug treatment of both adults and adolescents. Nevertheless, there is relatively little research on the validity of measures of readiness to change among treated adolescents. The purpose of this study was to compare three measures of readiness to change marijuana use commonly used in clinical research and practice with adolescents: the Readiness Ruler, the Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES; Factors 1 and 2, Recognition and Taking Steps, respectively), and a staging algorithm. The participants were 174 adolescents presenting for intensive outpatient alcohol and drug treatment who reported current marijuana use at the initial assessment. Evidence for concurrent validity was assessed by computing simple correlations among readiness measures, and correlations of each readiness measure with marijuana involvement (percentage of days abstinent in the last 30 days, problem severity score, and marijuana abuse and dependence symptom count [based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria]) at both the initial/baseline assessment and at a 6-month follow-up assessment. Evidence for predictive validity was based on the results of multilevel regression models of the readiness measures in predicting frequency of marijuana use, symptoms, and problems at 6 months from the initial readiness assessment and then in predicting marijuana use, symptoms, and problems at 12 months from the readiness assessment at 6 months. The results showed evidence for good concurrent and predictive validity for the ruler, the staging algorithm, and Taking Steps but poor evidence for the validity of Recognition. The ruler emerged as the measure with the most clinical utility when brevity and ease of administration are taken into account. Research and clinical implications of the findings are discussed.