[1] Australian Natl Univ, Natl Ctr Epidemiol & Populat Hlth, Canberra, ACT, Australia
[2] Canberra Hosp, Dept Cardiol, Canberra, ACT, Australia
[3] Univ Queensland, Dept Med, Brisbane, Qld, Australia
[4] Univ Newcastle, Ctr Clin Epidemiol & Biostat, Newcastle, NSW 2308, Australia