Assessing motivation for change in subjects with alcohol problems: the MAC2-A questionnaire.

AIMS This article presents the validation study of a questionnaire (MAC2-A), created to assess motivation for change in Italian adult subjects with alcohol related problems who require or are referred for assessment and treatment. The questionnaire evaluates readiness to change (RTC), self-efficacy and discrepancy. METHODS The questionnaire was validated on 419 subjects referred to 23 health agencies in Italy. RESULTS The questionnaire showed good internal consistency and temporal stability. Exploratory and confirmatory factor analysis confirms the consistency with the theoretical assumptions. Test-retest showed high reliability on all scales except one. Visual analogue control scales used for reliability and concurrent validity yielded strong correlations with the corresponding variables. CONCLUSION The study confirms the validity of the instrument, and its consistency with the model. The MAC2-A questionnaire is the first psychometric instrument integrating three factors (discrepancy, self-efficacy, RTC) into a 3D model of motivation for change.