J Clin Epidemiol 2019 10 28;114:38-48. Epub 2019 May 28.
Nuffield Department of Primary Care Health Sciences, Radcliffe Observatory Quarter, University of Oxford, Oxford OX2 6GG, UK; Academic Centre of General Practice, University of Leuven, Kapucijnenvoer 33 blok J, Bus 7001, 3000 Leuven, Belgium.