1 Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's, PT Government Associate Laboratory, Braga/Guimarães, Portugal; Respiratory Department, H. Sª Oliveira, Guimarães, Portugal. Electronic address: duartearaujodr@sapo.pt.
2 Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's, PT Government Associate Laboratory, Braga/Guimarães, Portugal.
3 Department of Pneumology, Centro Hospitalar de S. João, Porto, Portugal; Faculty of Medicine (FMUP), University of Porto, Portugal.
4 Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's, PT Government Associate Laboratory, Braga/Guimarães, Portugal; Horizonte Family Health Unit, Matosinhos, Portugal.