Assessment of eating disorders: comparison of interview and questionnaire data from a long-term follow-up study of bulimia nervosa.
OBJECTIVE: This paper examines diagnostic agreement between interview and questionnaire assessments of women participating in a long-term follow-up study of bulimia nervosa. METHODS: Women (N = 162) completed follow-up evaluations comprising questionnaires and either face-to-face or telephone interviews. RESULTS: Consistent with previous research, rates of eating disorders were higher when assessed by questionnaire than when assessed by interview; however, rates of full bulimia nervosa were similar. Overall diagnostic agreement was adequate for eating disorders (kappa=.64) but poor for bulimia nervosa (kappa=.49), with greater agreement between questionnaires and telephone interviews (kappa's range: .67-.71) than between questionnaires and face-to-face interviews (kappa's range: .35-.58). CONCLUSION: Findings support the possibility that increased rates of eating pathology on questionnaire assessments may be due, in part, to increased candor when participants feel more anonymous. Questionnaire assessments may not be inferior to interview assessments; they may reveal different aspects of disordered eating.