A new questionnaire specifically designed for patients affected by chronic obstructive pulmonary disease

Summary The aim of this study was to develop a specific and valid questionnaire for Italian COPD patients, living on the north or the south of Italy—which are two culturally distinct areas. The project consisted in three steps: (1) initial item set generation to identify items relevant to both genders, all ages and both regions; (2) item reduction including tests of regional specificity; (3) tests of internal validity using item-response theory using Rasch one-parameter modelling. Ninty-six COPD patients (mean aged 69 yr; 78 Male) completed the original set of 124 items of the Italian Health Status Questionnaire (IHSQ). Item reduction was carried out using an established standardised approa…