“…A subset of a previously collected data was used in this study based on the pre-specified eligibility criteria [4]. Briefly, the subset of data was obtained from January to September 2014 in a retrospective cohort study with all patients being either dengue immunoglobulin M or nonstructural 1 antigen positive, or both dengue immunoglobulin M and nonstructural 1 antigen positive, with clinical diagnosis of dengue with warning signs or severe dengue based on WHO The eligibility criteria in this study were patients presenting with vomiting or/and diarrhoea at the earliest day of illness without any other warning signs.…”