The reliability and discriminant validity of three potential measures of bulimic behaviours

There is currently a need for a reliable and valid self-report measure of bulimic behaviours that is brief and economical to administer and that can be used to assess response to treatment and to investigate correlates of bulimic symptoms. Three potential screening measures of bulimic behaviours (the Bulimia Test, the Conroy-Healy Eating Questionnaire and the Bulimia subscale of the Eating Disorder Inventory) were evaluated using internal consistency analysis and Receiver (or Relative) Operating Characteristic curve analysis, to determine their internal reliability and ability correctly to identify bulimic patients seen at an eating disorders outpatients clinic. The results showed that the three measures examined were all good discriminators of bulimic and non-bulimic patients. However, the results showed that the Bulimia Test was clearly the most reliable measure, apparently because of its greater length. It is suggested that further investigations be conducted to establish the sensitivity of the Bulimia Test to changes in the severity of bulimic behaviours in patients, since this will increase knowledge of its utility as a measure of response to treatment.