Patient-reported cognitive functioning and daily functioning in chronic dialysis patients

Subjective cognitive impairment negatively affects daily functioning, health-related quality of life, and health care consumption, and is predictive of future cognitive decline in many patient populations. However, no subjective measures of multidimensional cognitive functioning have been evaluated for dialysis patients. Our purposes were to examine (1) the association between patient-reported (subjective) cognitive functioning and objective cognitive functioning and (2) the relationships between subjective and objective cognitive functioning and everyday functioning of dialysis patients. We used baseline data from an ongoing longitudinal observational study of trajectories in dialysis patients' multidimensional quality of life. One hundred thirty-five patients completed a telephone-based neuropsychological battery (Brief Test of Adult Cognition by Telephone, a measure of objective cognitive functioning), a measure of subjective cognitive functioning (Patient's Assessment of Own Functioning Inventory), and measures of everyday functioning (Activities of Daily Living [ADL] and Instrumental Activities of Daily Living [IADL] scales). After controlling for age and education, there was a modest correlation (r = 0.33, P > 0.001) between subjective and objective cognitive functioning. Multivariate logistic regression models showed subjective, but not objective, cognitive functioning was a significant predictor of both ADLs and IADLs. The findings suggest the potential clinical value of subjective measures of cognitive functioning, not to replace objective measures or diagnostic tests, but rather to optimize the meaningfulness of clinical assessment and management.