[1] Royal Prince Alfred Hosp, Dept Colorectal Surg, Sydney, NSW, Australia
[2] Royal Prince Alfred Hosp, Surg Outcomes Res Ctr SOuRCe, Sydney, NSW, Australia
[3] Univ Sydney, Sch Publ Hlth, Sydney, NSW, Australia
[4] Royal Prince Alfred Hosp, Inst Acad Surg, Sydney, NSW, Australia