Geographical distribution of GEIRD centers in Italy.
As part of GEIRD stage-1, a cross-sectional screening questionnaire was administered between 2006 and 2010 to 18,357 subjects from the general Axitinib aged 20–44, living in one of the seven GEIRD centers. The GEIRD screening questionnaire (www.geird.org) is a modified version of the European Community Respiratory Health Survey (ECRHS) questionnaire, and included items on the occurrence of allergic diseases, socio-demographic characteristics and environmental exposures (de Marco et al., 1999). The questionnaire was mailed up to 3 times in the case of non-response, and a cycads final phone interview was carried out to reach the remaining non responders. Participants were informed about all the research aspects and consented to complete and return the questionnaire. Approval to conduct the study was granted from the local ethical committee in each participating center.
2.2. Respiratory outcomes
A subject was classified as having: