Author G. Nakafero M. Grainge A. Valdes N. Townsend C. Mallen W. Zhang M. Doherty M. Mamas A. Abhishek Year of Publication 2019 DOI 10.1136/bmjopen-2019-032050 DOIGoogle ScholarBibTeXEndNote X3 XMLEndNote 7 XMLEndnote taggedMarcRIS