Bolland Mark J, Avenell Alison, Grey Andrew
Department of Medicine, University of Auckland, Private Bag 92 019, Auckland 1142, New Zealand.
Health Services Research Unit, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK.
BMJ. 2018 Nov 15;363:k4755. doi: 10.1136/bmj.k4755.