Validation of a questionnaire for self-rating of urological and gynaecological morbidity after treatment of gynaecological cancer

Abstract

Background and purpose: Patient self-assessment of symptom severity provides clinicians and researchers with important information. It is crucial to evaluate the validity of a self-assessment questionnaire in the context of its intended use. The objective of this study was to evaluate the validity of the uro-gynaecological questionnaire (UGQ), a new instrument for patient self-assessment of urological-, genital-, menopausal-, and pain symptomatology in gynaecological cancer patients. Material and methods: The UGQ was developed after literature review, patient- and expert interviews and pilot testing. From February 1992 to October 1992, 88 gynaecological cancer patients were invited to participate in a validation study after the initiation of their primary radiotherapy or chemotherapy. The method of validation investigated whether patients and researchers interpreted the items of the questionnaire in the same way. The patient's written response before interview was compared with an observer rating of the patient's open-ended audio-taped responses to the same questionnaire, administered as an interview. Qualitative recordings by the observer were made to describe potential misinterpretations. Results: The agreement between the patient's and the observer's ratings was high: the median overall agreement was 0.91 (range 0.71–1.00) and the median kappa was 0.88 (range 0.45–1.00). The quantitative and the qualitative results identified a few minor validity problems; especially, the issue of selective reporting, i.e. some patients only reporting those symptoms they considered relevant for the study, which may lead to systematic errors. Conclusions: The results strongly suggest that patients interpret the UGQ items as intended, i.e. they are valid. The UGQ is recommended for patient self-assessment of uro-gynaecological morbidity in gynaecological cancer patients.