Discrepancies between cognition and decision making in older adults.

Abstract

There is increasing clinical and legal interest in discrepancies between decision-making ability and cognition in old age, a stage of life when decisions have major ramifications. We investigated the frequency and correlates of such discrepancies in non-demented older adults participating in a large community-based cohort study of aging, the Rush Memory and Aging Project. Participants [n=689, mean age 81.8 (SD 7.6), mean education 15.2 (SD 3.1), 76.8% female and 93.3% white] completed a measure of financial and healthcare decision making (DM) and a battery of 19 neuropsychological tests from which a composite measure of global cognition (COG) was derived. Results indicated that 23.9% of the sample showed a significant discrepancy between DM and COG abilities. Of these, 12.9% showed DM<COG, while 11.0% showed DM>COG. Logistic regression models showed older age, being non-white, greater temporal discounting, and greater risk aversion were associated with higher odds of being in the DM<COG group. Being male was associated with higher odds of being in the DM>COG group. Education, income, depressive symptoms, and impulsivity were not associated with a discrepancy. Only demographic associations (age, sex, and race) remained significant in a fully adjusted model with terms included for all factors. These results support the consideration of decision making and cognition as potentially separate constructs.