Welcome to the Combined Assessment of Risk Encountered in Surgery (CARES) surgical risk calculator. This calculator was derived from a cohort of 79,914 patients in Singapore and provides a prediction of both postoperative mortality and need for ICU admission after surgery based on certain variables. The development of this calculator was published here1. Please select the correct variables to generate the risk estimates.


The CARES Surgical Risk Calculator estimates the risk of (i) prolonged admission in the ICU for more than 24 hours after surgery, and (ii) death within 30 days after surgery. The risk estimates generated are only estimates, based on the certain variables selected. This is not a patient-specific estimate, and there may be other factors that affect a patient’s outcome which are not included in this Risk Calculator. The information presented here is provided on the understanding that no surgical or medical advice or recommendation is being rendered. Medical advice has to be individualized and can only be rendered after adequate assessment of your condition through appropriate clinical examination. Please do not disregard the professional medical advice of your physician or local healthcare provider. The information obtained from this website is not intended to replace the advice of a medical practitioner and/or healthcare provider. The CARES Surgical Risk calculator is not responsible for medical decisions that are made based on the risk calculator estimates, since these estimates should always be correlated with the individual patient profile. Singapore Health Services Pte Ltd and Duke-NUS Medical School and their related companies and respective employees and agents do not make any representations and expressly disclaim any and all warranties regarding the Risk Calculator, whether express or implied, including but not limited to representations or warranties pertaining to merchantability, fitness for a particular purpose, accuracy, validity, and/or completeness of information. In connection with your use of this Risk Calculator, we will not be liable directly or indirectly for personal injury including death, property damage, loss of use, business interruption, loss of profits, or any direct, indirect, special, incidental or consequential damages, however caused and under any basis of liability, whether for breach of warranty, contract, tort (including negligence), strict liability or otherwise.


  1. Chan DXH, Sim YE, Chan YH, Poopalalingam R, Abdullah HR. Development of the Combined Assessment of Risk Encountered in Surgery (CARES) surgical risk calculator for prediction of postsurgical mortality and need for intensive care unit admission risk: a single-center retrospective study. BMJ Open. 2018 Mar 23;8(3):e019427. Pubmed Original article
  2. Lee TH, Marcantonio ER, Mangione CM, Thomas EJ, Polanczyk CA, Cook EF, et al. Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation. 1999 Sep 7;100(10):1043–9. Pubmed Original Article

Page updated: 18 April 2018