In the nested Sleep Apnea, Neuroinflammation, and Dysfunctional Cognition Manifesting After New Elective Surgery (SANDMAN) cohort substudy, the first eligible 80 INTUIT patients (ie, those not already on home continuous positive airway pressure therapy) will undergo preoperative home sleep testing to measure sleep apnea severity(apnea-hypopnea index [AHI]). Multivariate analysis willdetermine the extent to which AHI is associated with POCD severity and/or CSF cytokine levels.