Jens-Tore Granslo*, Magne Bråtveit, Bjørg E Hollund, Ågot Irgens, Cecilie Svanes, Nils Magerøy and Bente E Moen
* Corresponding author: Jens-Tore Granslo jens-tore.granslo@helse-bergen.no
BMC Pulmonary Medicine 2012, 12:76 doi:10.1186/1471-2466-12-76