[1] Cabrini Hosp, Dept Clin Epidemiol, Malvern, Vic 3144, Australia
[2] Monash Univ, Dept Epidemiol & Prevent Med, Cabrini Med Ctr, Malvern, Vic 3144, Australia
[3] Vrije Univ Amsterdam, Med Ctr, Inst Res Extramural Med, Amsterdam, Netherlands
[4] Erasmus Univ, Rotterdam, Netherlands
[5] Univ Maastricht, Maastricht, Netherlands
[6] Dutch Coll Gen Practitioners, Utrecht, Netherlands
[7] Nivel Netherlands Inst Hlth Serv Res, Utrecht, Netherlands