Self‐ and interviewer‐reported cognitive problems in relation to subsequent cognitive decline and dementia: results from two prospective studies

Abstract

AbstractBackgroundLittle is known regarding the overall association of self‐reported cognitive problems (SCP) and interviewer‐reported cognitive problems (ICP) with age‐related cognitive decline in later life.MethodWe included 10976 Chinese (age: 57.7 ± 8.7) and 40499 European (age: 64.6 ± 9.4) adults without dementia at baseline from CHARLS and SHARE, respectively. Self‐rated current memory (5‐point scale) and interviewer‐rated frequencies of asking for clarification (6‐point scale) were used to define SCP and ICP (dichotomized). Outcomes included objective cognitive test scores (z‐transformed) and incident dementia. We performed generalized estimating equation models to evaluate mean differences in objective cognitive decline (z‐score) across groups. Logistic regression and cox proportional hazards models were used to estimate relative risk of dementia.ResultDuring an average of 5.4 and 5.7 years of follow‐up, rates of cognitive decline were ‐0.039 (‐0.044, ‐0.034) z‐score/year for Chinese and ‐0.027 (‐0.029, ‐0.025) z‐score/year for Europeans. Compared to those without SCP and ICP, participants with coexistence of SCP and ICP were associated with faster cognitive decline (βCHARLS: ‐0.051 [‐0.080, ‐0.021]; βSHARE: ‐0.024 [‐0.043, ‐0.004]; Pooled β: ‐0.035 [‐0.061, ‐0.009] z‐score per year). In addition, individuals with both SCP and ICP had higher risk of developing dementia (ORCHARLS: 1.77 [1.42, 2.20]; HRSHARE: 2.94 [2.42, 3.59]; Pooled relative risk: 2.29 [1.38, 3.77]).ConclusionCombination of SCP and ICP could be utilized as strong early indicators to identify individuals at high risk of cognitive decline and dementia.