1Dept of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Yoshidakonoecho, Sakyoku, Kyoto 606-8501, Japan
2Dept of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
3Dept of Surgery, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
4Dept of Clinical Oncology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
5Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, Netherlands