Treating obesity: can the stages of change model help predict outcome measures?

Background: The transtheoretical model of behaviour change the 'Stages of Change' by Prochaska & Di Clemente (1982) has been advocated for enhancing dietary counselling. It has been suggested that understanding where people are in the stages of change model could lead to targeting of advice and improved outcome of dietetic management such as weight loss in the obese and reduced did not attend rates. This study assessed whether a six-question staging model of the stages of change could predict which patients are most likely to not attend an appointment and predict those who will lose weight. Methods: Prior to the start of their dietetic interview, obese outpatients completed a simple 'stages of change questionnaire' (SCQ). This assessed where the patient was in the stage of change cycle, motivation to lose weight, how easy they thought this would be and attendance rate. Patients who did not attend were sent a SCQ in the post. Results: There were no significant differences in SCQ scores at visit one, between patients attending twice (group 1) and those who did not attend their second appointment (group 2). By visit two, 72% of group 1 who were in the action or maintenance stage of the cycle had lost 1.5 +/- 2.4% body weight, and were more optimistic and committed to doing so. There was no correlation between percentage weight loss and the first SCQ score in group 1 (r = 0.05, P = 0.73). It is of interest that no subject in group 3, i.e. those who did not attend both appointments, returned any of the SCQs after the first mailing and only 17% of this group returned one after a reminder was sent. Conclusion: Evidence from this study would suggest that the stages of change model does not distinguish between which patients will not attend a second appointment or lose weight. However, it may help identify motivated patients if used as a postal screening tool.