Han Y, et al. - Whether preoperative screening of salivary cortisol levels may help identify patients at elevated risk for postoperative cognitive dysfunction (POCD), was investigated in this study with 120 patients (>60 years of age) undergoing major noncardiac surgery who also had neuropsychological testing 1 day before and 1 week after surgery. Saliva samples obtained in the morning and the evening 1 day before surgery were analyzed. Researchers detected POCD in 17.02% (16 of 94) of patients 1 week after the operation. Even after adjusting for the Mini-Mental Sate Examination score, early POCD onset was predicted by a higher preoperative AM (morning)/PM (evening) salivary cortisol ratio, with area under the receiver operating characteristic curve of 0.72 for the salivary cortisol AM/PM ratio in individuals with POCD. With a sensitivity of 50% and specificity of 91%, 5.69 was identified as the optimal cutoff value. Preoperative salivary cortisol AM/PM ratio could be potentially useful for screening patients for an increased risk.