RT Journal Article SR Electronic T1 Letter to the editor: authors’ response JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 490 OP 491 DO 10.1136/thoraxjnl-2014-206708 VO 70 IS 5 A1 Alexandra L Quittner A1 Dave Barker A1 Lutz Goldbeck A1 Alistair Duff A1 Janice Abbott YR 2015 UL http://thorax.bmj.com/content/70/5/490.1.abstract AB