Dialysis modality and cognitive outcomes in chronic kidney disease: a systematic review and meta-analysis

Background Cognitive impairment is a prevalent comorbidity in patients with chronic kidney disease (CKD). While hemodialysis (HD) and peritoneal dialysis (PD) are established renal replacement therapies, their relative effects on cognitive outcomes remain unclear. This meta-analysis compared cognitive outcomes between HD and PD in CKD patients. Methods The protocol was prospectively registered on PROSPERO (CRD42024602533). PubMed, CENTRAL, Embase, Medline, Web of Science, PsychInfo, and CINAHL were searched from January 2000 to January 2025. Eligible studies included cohort studies of adult patients undergoing HD versus PD. Primary outcomes were cognitive function and dementia incidence. A random-effects meta-analysis model was used. Risk of bias was assessed using ROBINS-I, and evidence quality was evaluated using GRADE. Methodological rigor was benchmarked against previous reviews using AMSTAR 2.0. Results The search identified 1489 studies, of which 26, involving 326,216 patients, were included. There was a statistically significant difference in overall cognitive function between HD and PD (SMD: −0.46; 95% CI: −0.62 to –0.29; p < 0.00001; I 2 = 49%), and dementia incidence (OR: 1.68; 95% CI: 1.25 to 2.25; p = 0.0006; I 2 = 94%). Subgroup and qualitative analyses suggested PD offers advantages in executive function, verbal memory, and cognitive stability. Conclusions Quantitative analyses revealed significant evidence, and qualitative trends suggest PD may be associated with better cognitive outcomes in select domains. These findings underscore the need to individualize dialysis modality decisions based on cognitive risk profiles and conduct further standardized research.