Head injury at different ages and cognitive performance in a diverse cohort: Findings from the KHANDLE Study

Abstract

AbstractBackgroundEvidence is limited on the impact of a head injury and the role of age at injury on different cognitive domains, particularly among in diverse cohorts.MethodsThe Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study examines cognitive aging across four racial/ethnic groups (29% White, 26% Black, 24% Asian, & 20% Latino). Head injury was determined by asking: “Have you ever had a head injury where you lost consciousness or for which you received medical care?” Age at first injury was grouped as 0‐15, 16‐29, 30‐64 and 65+ years. Education was coded as college graduate or more and less than college graduate. Z‐standardized measures of verbal episodic memory, semantic memory, and executive function were assess using the Spanish and English Neuropsychological Assessment Scales (SENAS). The association between head injury and cognitive domains were analyzed with adjustment for age, sex, race, and education using multivariable linear regression models.ResultsAmong the analytic sample of 1,666 participants, 392 (22.9%) reported history of a head injury. Exposure to head injury was not associated with deficits in executive function (β=0.04, 95% CI: −0.05, 0.14), verbal episodic memory (β=‐0.09, 95% CI: −0.02, 0.10), or semantic memory (β=0.07, 95% CI: −0.02, 0.16). Among those reporting a head injury, 77.1% experienced one injury, 15.5% 2 injuries, 4.6% 3 injuries, and 6.7% participants reported 4+ injuries. The median (interquartile range) age at first head injury was 24 (13‐60) years, and time since first head injury was 48 (14‐61) years. Age at first head injury was not associated with cognitive function when compared to individuals without a head injury (Table 1A). Among those with a history of head injury, age at first injury was not associated with executive function (65+ vs. 0‐15 years: β=‐0.25, 95% CI: −0.50, 0.01), verbal episodic memory (65+ vs. 0‐15 years: β=0.21, 95% CI: −0.05, 0.47), or semantic memory (65+ vs. 0‐15 years: β=‐0.09, 95% CI: −0.32, 0.13) (Table 1B).ConclusionParticipants who reported a head injury did not exhibit worse cognition compared to those without history of injury nor was age at first head injury associated with any cognitive domain.