To test whether measures of readiness to change (RTC) re-assessed every 3 months had predictive value for change in alcohol use over 12 months in a sample of adult outpatients with alcohol use disorder (AUD).
Of the case, 78 outpatients were followed monthly over one year and averaged 9.0 interviews each (total observations = 704). Alcohol abstinence days and heavy drinking days were assessed monthly using a 30-day timeline follow-back procedure. RTC was assessed using 3 'readiness rulers' (importance, readiness, and confidence to change, measured on a 0-10 visual analog scale). The effect of RTC on alcohol use over time was tested every 3 months using negative binomial generalized estimating equations (GEE), controlling for gender, age, baseline alcohol dependence severity and AUD treatment status (ongoing vs. ceased).
GEE models showed highly significant effects of readiness and confidence to change on respective alcohol outcomes. Effects of importance to change were weaker.
As hypothesized, higher RTC scores were associated with improved alcohol use outcomes in this longitudinal study. The strongest effects were for confidence to change. Finding significant predictive validity prospectively is consistent with a theoretical view of RTC as a dynamic construct. Further research might clarify how AUD treatment could actually elicit or increase RTC.