Background
Prevalence of moderate to severe cognitive impairment among hemodialysis patients is more than double the prevalence in the general population. This study describes cognitive impairment occurrence in a peritoneal dialysis cohort compared with a cohort without chronic kidney disease (CKD).
Study Design
Cross-sectional study.
Setting and Participants
51 English-speaking peritoneal dialysis patients from two urban dialysis units, compared with 338 hemodialysis patients from 16 urban dialysis units and 101voluntary controls without CKD from urban general medicine clinics.
Predictor
A 45-minute battery of nine validated neuropsychological tests (cognitive domains memory, executive function, language).
Outcomes
Mild, moderate, or severe cognitive impairment, classified according to a previously designed algorithm.
Results
Of the peritoneal dialysis cohort, 33.3% had no or mild, 35.3% moderate, and 31.4% severe cognitive impairment; corresponding values were 60.4%, 26.7%, and 12.9% of the non-CKD cohort, and 26.6%, 36.4%, and 37.0% of the hemodialysis cohort. A logistic regression model including age, sex, race, education, hemoglobin, diabetes, and stroke showed that only non-white race (P = 0.002) and education (P = 0.002) were associated with moderate to severe cognitive impairment in the peritoneal dialysis cohort. Compared with hemodialysis patients, more peritoneal dialysis patients had moderate to severe memory impairment (60% vs. 52%), but fewer had impaired executive function (one-third vs. one-half). Peritoneal dialysis was associated with a more than 2.5-fold increased risk of moderate to severe cognitive impairment compared with no CKD (OR, 2.58; 95% confidence interval 1.02-6.53), as was hemodialysis (OR, 3.16; 95% CI, 1.91-5.24), in an adjusted logistic regression model.
Limitations
Small sample size, participation rate somewhat low.
Conclusions
Similar to hemodialysis patients, two-thirds of peritoneal dialysis patients had moderate to severe cognitive impairment, enough to interfere with safely self-administering dialysis and adhering to complex medication regimens. These patients could benefit from cognitive assessment before and periodically after dialysis initiation.