RT Journal Article SR Electronic T1 Author's response: understanding the natural progression in %FEV1 decline in patients with cystic fibrosis: a longitudinal study JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 294 OP 295 DO 10.1136/thoraxjnl-2012-202954 VO 68 IS 3 A1 Taylor-Robinson, David A1 Whitehead, Margaret A1 Diderichsen, Finn A1 Olesen, Hanne Vebert A1 Pressler, Tania A1 Smyth, Rosalind A1 Diggle, Peter YR 2013 UL http://thorax.bmj.com/content/68/3/294.2.abstract AB