Cognitive complexity of clients and counsellors during motivation-based treatment for smoking cessation: an observational study on occasional smokers in a US college sample.

OBJECTIVE: Motivational interviewing (MI) is a widely used and promising treatment approach for aiding in smoking cessation. The present observational study adds to other recent research on why and when MI works by investigating a new potential mechanism: integrative complexity.

SETTING: The study took place in college fraternity and sorority chapters at one large midwestern university.

PARTICIPANTS: Researchers transcribed MI counselling sessions from a previous randomised controlled trial focused on tobacco cessation among college students and subsequently scored clients' and counsellors' discussions across four counselling sessions for integrative complexity.

INTERVENTIONS: This is an observational secondary analysis of a randomised controlled trial that tested the effectiveness of MI. We analysed the relationship between integrative complexity and success at quitting smoking in the trial.

PRIMARY AND SECONDARY OUTCOME MEASURES: Success in quitting smoking:Participants were categorised into two outcome groups (successful quitters vs failed attempters), created based on dichotomous outcomes on two standard variables: (1) self-reported attempts to quit and (2) number of days smoked via timeline follow-back assessment procedures that use key events in participants' lives to prompt their recall of smoking.

RESULTS: We found (1) significantly higher complexity overall for participants who tried to quit but failed compared with successful quitters (standardised β=0.36, p<0.001, (Lower Confidence Interval.) LCI =0.16, (Upper Confidence Interval) UCI =0.47) and (2) the predictive effect of complexity on outcome remains when controlling for standard motivational and demographic variables (partial r (102)=-0.23, p=0.022).

CONCLUSIONS: Taken together, these results suggest that cognitive complexity is uniquely associated with successful quitting in MI controlled trials, and thus may be an important variable to more fully explore during treatment.