Protocol for an OpenSAFELY cohort study collecting patient-reported outcome measures using the TPP Airmid smartphone application and linked big data to quantify the health and econ... oleh Michael Marks, Mark Jit, Frank Sandmann, Ben Goldacre, Liam Smeeth, Laurie A Tomlinson, Liang-Yu Lin, Emily Herrett, Deb Smith, Jessica Morley, Andrew Briggs, Seb Bacon, Amir Mehrkar, John Parry, Keith Tomlin, Viyaasan Mahalingasivam, Christopher Bates, Benjamin Butler-Cole, Alan Dennison, Ethan Gabriel, Rosalind M M Eggo