Education Levels and Poststroke Cognitive Trajectories.

Importance: Acute stroke is associated with accelerated, years-long cognitive decline. Whether education levels are associated with faster cognitive decline after stroke is unclear. Objective: To evaluate the association of education level with poststroke cognitive decline and to determine whether age at stroke modifies the association. Design, Setting, and Participants: Individual participant data meta-analysis of 4 US cohort studies (January 1971 to December 2019). Analysis began August 2022 and was completed in January 2024. Exposures: Education level (less than high school, completed high school, some college, and college graduate). Main Outcomes and Measures: Harmonized cognitive outcomes were global cognition (primary outcome), memory, and executive function. Outcomes were standardized as t scores (mean [SD], 50 [10]); a 1-point difference represents a 0.1-SD difference in cognition, with higher score representing better function. Linear mixed-effect models estimated the trajectory of cognitive decline after incident stroke. Results: The analysis included 2019 initially dementia-free stroke survivors (1048 female [51.9%]; median [IQR] age at stroke, 74.8 [69.0-80.4] years; 339 with less than a high school education [16.7%]; 613 who completed high school [30.4%]; 484 with some college [24.0%]; 583 with a college degree or higher [28.9%]). Median (IQR) follow-up time after stroke was 4.1 (1.8-7.2) years. Compared with those with less than a high school degree, college graduates had higher initial poststroke performance in global cognition (1.09 points higher; 95% CI, 0.02 to 2.17 points higher), executive function (1.81 points higher; 95%CI, 0.38 to 3.24 points higher), and memory (0.99 points higher; 95% CI, 0.02 to 1.96 points higher). Compared with stroke survivors with less than a high school education, there was a faster decline in executive function among college graduates (-0.44 points/y faster; 95% CI, -0.69 to -0.18 points/y faster) and those with some college education(-0.30 points/y faster; 95% CI, -0.57 to -0.03 points/y faster). Education level was not associated with declines in global cognition or memory. Age did not modify the association of education with cognitive decline. Conclusions and Relevance: In this pooled cohort study, the trajectory of cognitive decline after stroke varied by education level and cognitive domain, suggesting that stroke survivors with a higher education level may have greater cognitive reserve but steeper decline in executive function than those with a lower education level.