Prevalence of cognitive impairment among peritoneal dialysis patients: a systematic review and meta-analysis

Background Cognitive impairment (CI) is common among patients on peritoneal dialysis (PD), but it is under-recognized and systematic review on its prevalence and impact across different geographical locations or patient characteristics is lacking. Methods A search of the literature on CI in PD patients published between 1 Jan 1980 and 25(.)April 2019 was conducted. Meta-analysis using a random effects model was performed to determine the pooled estimate of the prevalence of CI. Meta-regression was performed to identify factors contributing to the variance of prevalence rate. A systematic review was also performed to study risk factors of CI and its impact on clinical outcomes. Results Eight studies were included and the relevant data from 1736 patients were extracted for analysis. Meta-analysis revealed a pooled prevalence of CI at 28.7% (95% CI 15.9-46%). Meta-regression analyses showed that the prevalence of CI was unrelated to patient's age, gender, duration of PD, healthcare policy of dialysis modality, the prospective or retrospective nature of studies, or year of publication. Systematic review of 20 studies showed that older age, female sex and lower education were risk factors for CI. Potential reversible factors for CI include electrolytes disturbances, depression and vitamin D deficiency. Also, CI was associated with a higher risk of hospitalization, mostly due to PD-related peritonitis. Conclusions CI is common in patients on long-term PD. Screening for CI should be considered in PD patients with increased risk.