Self-report versus interview data of women's subjective theories of illness: concordance and predictive validity in a psychosomatic-gynecological liaison service.

ABSTRACT

Between-method comparisons of patient data from standardized self-report instruments and corresponding patient interview data frequently have poor agreement. We investigated the concordance and predictive validity of self-report measures and expert-rated interview data of women's subjective theories of illness in a psychosomatic-gynecological consultation liaison service. 31 patients completed two questionnaires (KKG, PATEF) on subjective theories of illness and were interviewed with a semistructured instrument on the same topic at the time of the initial appointment and after 1.5 years. External criteria for assessing the predictive validity of questionnaire versus interview data were follow-up participation and psychotherapy utilization during the follow-up interval. Questionnaire and interview rating data were only modestly associated. Rater concordance on the interview data was low. Neither the initial-assessment interview nor the questionnaire data had predictive validity for patients' participation in the follow-up. None of the interview rating data but a portion of the questionnaire data, had predictive validity for patients' utilization of psychotherapy during the follow-up interval. The cognitive conceptualization of subjective theories of illness may fail in patients with psychosomatic disorders, due to their very mode of experience. A wider approach that includes assessment of nonverbal communication and countertransference might be useful.