[1] Concord Hosp, Dept Thorac Med, Concord, Australia
[2] Univ Sydney, Sydney Med Sch, Sydney, NSW, Australia
[3] Woolcock Inst Med Res, Glebe, NSW, Australia
[4] Macquarie Univ, Fac Med & Hlth Sci, N Ryde, NSW, Australia
[5] Royal North Shore Hosp, Dept Resp Med, St Leonards, NSW, Australia