RT Journal Article SR Electronic T1 Whose risk is it anyway? JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 799 OP 800 DO 10.1136/thoraxjnl-2013-203536 VO 68 IS 9 A1 David A Waller YR 2013 UL http://thorax.bmj.com/content/68/9/799.abstract AB