Acromegaly Quality of Life Questionnaire (AcroQoL).

Acromegaly is a chronic disease with an important impact on patients, Health Related Quality of Life (HRQoL). The ability to effectively measure Health Related Quality of Life is central to describing the impacts of disease or treatment upon the patient, therefore the importance of having a disease specific questionnaire for acromegaly. For the development of the AcroQoL questionnaire different sources of information were used: first a literature search was performed to identify relevant papers describing the impact of acromegaly in HRQoL, second the main domains of impact on HRQoL were identified by 10 experts endocrinologists, and third ten in-depth semi-structured interviews were conducted in acromegalic patients to identify domains and items related to the self-perceived impact of acromegaly in patients' life. After a proper qualitative analysis a preliminary 38 item questionnaire was obtained. Rasch analysis concluded with a final 22 item questionnaire. The measurement properties (validity and reliability) of the resulting final questionnaire were tested and compared using standard procedures (Cronbach's Alpha and item-total correlation). The evaluation of the item parameters confirmed the construct validity of the new instrument. Responsiveness to change was assessed in a small sample of 32 acromegalic patients with active disease in Spain who were administered the AcroQoL and the generic questionnaire EuroQoL 5-D. The results showed a statistically significant relationship between all the dimensions of AcroQoL and the VAS (visual analogic scale) of EQ-5D. An improvement in the global score of AcroQoL was related to a global improvement in the VAS of the EQ-5D. Following the current recommended standard methodology the Spanish questionnaire was translated into eleven other languages.