The Diagnostic Performance of Screening Instruments for Mild Cognitive Impairment and Dementia in Chronic Kidney Disease and Kidney Failure: A Systematic Review and Meta-analysis.

Rationale & Objective: Mild cognitive impairment (MCI) and dementia disproportionately affect people with chronic kidney disease (CKD) and kidney failure. Screening instruments can accurately identify cognitive impairment in the general population, but their performance in the setting of kidney disease is unclear. We aimed to summarize the performance of screening instruments for cognitive impairment in adults with CKD or kidney failure. Study Design: Systematic review and meta-analysis. Setting & Study Populations: Adults with CKD or kidney failure (dialysis or kidney transplantation). Selection Criteria for Studies: Studies published in Medline, EMBASE, CINAHL, Cochrane Library, and PsycINFO through October 2022, evaluating the diagnostic performance of cognitive screening instruments compared to a neuropsychological battery gold standard. Data Extraction: Study characteristics including population, screening instrument, gold standard, operating characteristics including sensitivity, specificity, odds ratio, and optimal cutoffs were extracted by 2 investigators. Conflicts were resolved through discussion with another reviewer. Analytical Approach: Random-effects models estimated pooled sensitivity, specificity, diagnostic odds ratio, and area under the receiver operating characteristic curve. Risk of bias was assessed using the QUality Assessment instrument for Diagnostic Accuracy Studies-2. Results: We included 10 studies involving >1,800 participants with CKD or kidney failure. The most frequently evaluated screening instruments were the Montreal Cognitive Assessment (MoCA) and the Mini-Mental Status Examination. For MCI/dementia, the MoCA had the best diagnostic performance using a cutoff of 24, with a pooled sensitivity and specificity of 0.94 (95% confidence interval [CI], 0.81-0.98) and 0.63 (95% CI, 0.35-0.85), respectively. Without any specific cutoff, the Mini-Mental Status Examination had a pooled sensitivity of 0.48 (95% CI, 0.28-0.69) and pooled specificity of 0.95 (95% CI, 0.78-0.99). Limitations: Small number of studies, absence of kidney transplantation and hemodiafiltration populations, selective reporting of operating characteristics for optimal cutoffs, and high degree of statistical heterogeneity. Conclusions: Although further research is needed to evaluate the operating characteristics of MCI/dementia screening instruments in CKD, dialysis, and kidney transplantation, based on the current evidence, we recommend using the MoCA with a threshold of 24.