The severity of the illness and the decline in health status of critical patients determine the mortality rate in ICUs. Extremes of age, disease severity, and certain pre-existing comorbidities like diabetes are the factors that contribute to higher hospital death rates (e.g. Malignancy, Immunosuppressed status and patients on renal replacement therapy). Florence Nightingale recognised the need for clinical treatment outcome assessment for the first time in 1863. 2