Wong DJN, Harris S, Sahni A, et al. - In view of the significance of preoperative risk prediction for guiding clinical decision-making and resource allocation, researchers sought to compare the performance of freely available objective surgical risk tools vs subjective clinical assessment in predicting 30-day mortality. During this 1-week cohort study performed in 274 hospitals in the UK, Australia, and New Zealand, they obtained data on risk and surgical outcome on every patient who had an operation requiring an overnight stay in hospital. Information concerning a subjective assessment of risk was obtained from the clinical team (surgeons, anaesthetists) looking after the patient. These assessments were then compared with the results of 3 freely available objective risk-assessment tools. Assessment of data obtained from 22,631 patients revealed that the accuracy of subjective assessment was equivalent to the best of the objective risk tools (the Surgical Outcome Risk Tool or SORT) for predicting death in hospital within 30 days of surgery. However, an even more accurate estimate can be achieved by combining subjective and objective measurement using the SORT.