Psychological factors associated with postoperative cognitive outcomes in older adults: a systematic review and meta-analysis

BACKGROUND: Older adults face increased risk of postoperative cognitive complications, which can prolong hospitalisation and impair function. Preoperative psychological factors may contribute to these cognitive outcomes, yet their impact remains unclear. This systematic review with meta-analysis synthesises evidence on associations between psychological factors and postoperative cognitive outcomes in older adults. METHODS: A systematic review and meta-analysis, including synthesis without meta-analysis, of studies reporting preoperative psychological factors and postoperative cognitive outcomes in adults aged 60 yr or older was conducted. Five databases (Medline, Embase, Web of Science, PsycINFO, and CINAHL) were searched. The Newcastle Ottawa Scale or Cochrane Risk of Bias 2.0 tool was used for quality appraisal. Where feasible, random-effects meta-analyses were conducted alongside P-value synthesis and vote counting based on direction of effect. RESULTS: Thirty studies (n=6714 subjects) were included. Four categories of psychological factors were identified: depression, anxiety, personality traits, and stress-related factors. Postoperative delirium was the most reported outcome, assessed in all studies with incidence ranging from 9% to 55.6%. Two studies assessed delayed neurocognitive recovery or postoperative neurocognitive disorder. In studies reporting effect estimates, the random-effects model showed a non-significant association between depression and postoperative delirium (odds ratio, 1.08; 95% confidence interval, 0.97-1.20). In the synthesis without meta-analysis, there was evidence of an association between the psychological factors and postoperative cognitive outcomes in 28 studies (P