Sze Shyang Kho1, Yoke Fun Ho2, Swee Kim Chan3, Siew Teck Tie3. 1. Division of Respiratory Medicine, Department of Medicine, Sarawak General Hospital, Ministry of Health, Kuching, Sarawak, Malaysia. Electronic address: khosze@moh.gov.my. 2. Department of Medicine, Bintulu Hospital, Ministry of Health, Bintulu, Sarawak, Malaysia. 3. Division of Respiratory Medicine, Department of Medicine, Sarawak General Hospital, Ministry of Health, Kuching, Sarawak, Malaysia.