*BMC Geriatrics* 2018; 18:307
*Thorax* 2018; 73(10):918-925
*BMJ Open* 2018; 8:e019218
*British Journal of Dermatology* 2018; 179(1):63-71
*Pilot and Feasibility Studies* 2017; 3:25
*Annals of the Rheumatic Diseases* 2017; 76:227-234
*BMJ Open* 2016; 6(8):e011996
*Lancet* 2016; 387(10020):779-786
*American Journal of Respiratory and Critical Care Medicine* 2016; 201:A2727