1. Faculty of Medicine, Prince of Songkla University; Department of Anesthesia; Kanjanavanich street Ko-hong Hat Yai Thailand 90110
2. Prince of Songkla University; Epidemiology Unit, Faculty of Medicine; Hat Yai Songkhla Thailand 90110
3. Prince of Songkla University; Blood Bank and Transfusion Unit, Pathology; Faculty of Medicine Hat Yai Thailand 90110