Nonpharmacological interventions for preventing delirium in adult patients with cancer: a systematic review and meta-analysis

PURPOSE: To determine whether nonpharmacological interventions reduce delirium incidence in adult patients with cancer and to identify effective intervention strategies. METHOD: We conducted a systematic review and meta-analysis following PRISMA guidelines. PubMed, CENTRAL, CINAHL, and Ichushi-Web were searched through September 30, 2024, for randomized controlled trials (RCTs). Two authors independently extracted data, assessed the risk of bias using the Cochrane Risk of Bias 2 tool, and evaluated the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. The primary outcome was delirium incidence. A random-effects model was used for the meta-analysis. The study protocol was registered with UMIN-CTR (No. UMIN000051804; registered August 2, 2023). RESULTS: Overall, 12 RCTs involving 2,747 patients were included. Interventions were categorized into multicomponent interventions, bright light therapy, rehabilitation, and anesthesia or oxygen management. The meta-analysis of five trials showed that multicomponent interventions significantly reduced delirium incidence (risk ratio [RR], 0.43; 95% confidence interval [CI], 0.31-0.60; moderate-certainty evidence), with benefit predominantly observed in postoperative settings. The evidence for bright light therapy was inconclusive (RR, 0.31; 95%CI, 0.07-1.31; very low-certainty evidence). Most of the included studies had concerns regarding the risk of bias, mainly due to a lack of blinding. CONCLUSION: Multicomponent nonpharmacological interventions may reduce delirium incidence in adult patients with cancer, particularly in postoperative or perioperative settings. However, the certainty of evidence is moderate, and the included studies vary in patient populations, intervention components, and healthcare settings. Evidence for standalone interventions and prevention strategies in palliative or end-of-life care remains limited and inconclusive.