Chen Y, et al. - This study was undertaken to investigate the discriminatory value of the modified frailty index (mFI) to prognosticate postoperative delirium (POD) and delayed neurocognitive recovery after total joint arthroplasty (TJA). Between January 2018 and December 2019, researchers recruited a total of 383 individuals admitted for primary elective TJA under general anesthesia combined with inhalation agents over the period. The potential risk factors for POD and delayed neurocognitive recovery were screened by conducting a multivariate logistic regression analysis. In elderly subjects following TJA, the modified frailty index may be a promising prognosticator for both POD and delayed neurocognitive recovery. For risk stratification, Preoperative mFI evaluation can be applied and gives significant potential in clinical application.