Correlates of cognitive impairment in patients with chronic kidney failure on haemodialysis: Systematic review and meta‐analysis

AIM: To review and identify correlates of cognitive impairment in patients with chronic kidney failure (CKF) on haemodialysis. BACKGROUND: The literature is consistent with regard to the high prevalence of cognitive impairment among patients with CKF on haemodialysis and its dependence on multidimensional risk factors. DESIGN: Systematic review and meta-analysis based on Cochrane Handbook and PRISMA. DATA SOURCES: Electronic searches of the MEDLINE, EMBASE, Cochrane Library databases and major Korean databases were used. Only original research that assessed correlates of cognitive impairment in patients with CKF on haemodialysis and published between 2004-2016 in English or Korean were included. REVIEW METHODS: Studies were selected according to the PICOS: Population (chronic kidney failure patients with cognitive impairment on haemodialysis); Intervention (not applicable); Comparison (healthy controls or patients with chronic kidney failure on haemodialysis without cognitive impairment); Outcome (cognitive impairment); and Study design (primarily nonexperimental correlational studies and studies with experimental, quasi-experimental, or pre-post cohort designs). Q-test and I2 index were used to examine study homogeneity. RESULTS: A total of 39 studies were finally included. Age, gender, stroke history, difficulties in activities of daily life, haemoglobin levels, pain, sleep difficulties, and depression were found to be significant correlates of cognitive impairment. CONCLUSIONS: Nurses should be aware that the risk of cognitive impairment in patients with CKF on haemodialysis can be significantly higher for elders, women and in patients with a stroke, greater difficulties in activities of daily living, lower haemoglobin concentrations, higher pain levels, sleep difficulties, or depression.