Is stage of change enough? Confidence as a predictor of outcome in inpatient treatment for eating disorders.

Objective: While stage of change has been shown to be a robust predictor of eating disorder treatment outcome, little attention has been paid to the role of confidence. This study sought to better understand the role of confidence and the possible interaction it may have with stage of change in promoting eating disorder symptom change.

Method: Participants were adult women in inpatient treatment for eating disorders. They completed measures of motivation for change, which assessed precontemplation, action, confidence and internality (changing for oneself vs. others) and eating disorder symptom severity at pretreatment (N = 159) and posttreatment (n = 59). Only treatment completer analyses were used.

Results: Precontemplation and confidence had significant effects on pretreatment and posttreatment symptom severity, while action only had a significant effect on pretreatment symptoms. Confidence was shown to moderate relations between both measures of stage of change (i.e., precontemplation and action) and symptoms posttreatment. Follow-up analyses indicated that high precontemplation was associated with poor outcome, irrespective of confidence, however, low precontemplation was associated with better outcome at high levels of confidence. The interaction between confidence and action was also significant at very high levels of confidence. That is, among individuals who had high action at baseline, those with low confidence had significantly poorer outcomes relative to those with high confidence.

Discussion: Findings indicate that stage of change and confidence are both important prognostic factors and suggest that early behavior change in the absence of confidence may not guarantee best outcomes in inpatient eating disorder treatment.