1 Division of Family Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
2 Department of Family Medicine and Singapore Primary Care Cancer Network (SPRiNT), National University Health System, Singapore.
3 National University Polyclinics, National University Health System, Singapore.
4 Centre for Cancer Screening, Prevention and Early Diagnosis, Wolfson Institute of Population Health, Queen Mary University of London, United Kingdom.