Psychometric validation of two Italian quality of life questionnaires in menopausal women.

OBJECTIVE: To establish the psychometric properties of the Italian version of two quality of life (QOL) questionnaires in menopausal women: the psychological general well being index (PGWBI) and the women's health questionnaire (WHQ). METHOD: These questionnaires were translated into Italian and then self-administered to out-patient women a first time, 1 week later in stable women to assess reproducibility, and 3 months later to evaluate responsiveness over time. Baseline analyses included: factorial structure, multitrait analysis, internal consistency reliability, and clinical validity. RESULTS: Questionnaires were returned by 155 women (median age: 54 years, median duration of amenorrhoea: 56 months, median Kupperman index 26). Principal component analysis (PCA) of the PGWBI showed an important general factor and then, after rotation, three factors. The PCA of the WHQ showed ten factors. Only five reproduced the dimensions postulated à priori quite well. The item convergent validity was confirmed for all items of the major dimension of the two questionnaires, and the item divergent validity, although acceptable, was less satisfying for the PGWBI than the WHQ. The internal reliability was good (Cronbach's alpha > or = 0.70) for the PGWBI and for nine scales out of ten for the WHQ. The six dimensions of the PGWBI and most of the dimensions of the WHQ were significantly correlated to the Kupperman index, indicating the clinical validity of the instruments. The responsiveness to change in clinical status at 3 months was better in the PGWBI than in the WHQ with moderate effect size (around 0.5). CONCLUSION: The Italian versions of the PGWBI and the WHQ are reliable and useful for HRT clinical trials but the dimensional scores must be calculated bearing in mind the limitations in the structure. Other studies are needed to improve the factorial stability of certain WHQ dimensions. For the Italian version of the PGWBI, the validation process is to be completed by studies of mixed populations suffering from other types of disease.