RT Journal Article SR Electronic T1 Correction JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 239 OP 239 DO 10.1136/thoraxjnl-2013-204457.46.corr1 VO 69 IS 3 YR 2014 UL http://thorax.bmj.com/content/69/3/239.3.abstract AB