1. Clinical Research Centre, Sultanah Aminah Hospital, Johor, Malaysia
2. Penang Hospital, Penang, Malaysia; Clinical Research Centre, Sultanah Aminah Hospital, Johor, Malaysia
3. Sultanah Aminah Hospital, Johor, Malaysia; Department of Nephrology, Sultanah Aminah Hospital, Johor, Malaysia
4. Serdang Hospital, Selangor, Malaysia; Department of Nephrology, Sultanah Aminah Hospital, Johor, Malaysia
5. Kuala Lumpur Hospital, Kuala Lumpur, Malaysia; Department of Nephrology, Sultanah Aminah Hospital, Johor, Malaysia
6. Tuanku Jaafar Hospital, Negeri Sembilan, Malaysia; and Department of Nephrology, Sultanah Aminah Hospital, Johor, Malaysia