Supplementary Material for: Adjudication of Transient Ischemic Attack and Stroke in the Multi-Ethnic Study of Atherosclerosis

<b><i>Background:</i></b> To describe adjudication of transient ischemic attack (TIA) and stroke in an observational study. <b><i>Methods:</i></b> We detail the process used to adjudicate TIA and stroke in the Multi-Ethnic Study of Atherosclerosis (MESA), a large longitudinal cohort study. Two of three vascular neurologists adjudicated each event using specific protocols. We examined the initial agreement, effect of imaging on diagnosis of TIA versus ischemic stroke, and effect of strict and less strict criteria on the number of ischemic stroke subtypes classified as undetermined. <b><i>Results:</i></b> Of 573 adjudicated events over 13.5 years of follow-up, 95 (16.5%) had TIA and 269 (47.0%) had stroke: 211 (78.4%) ischemic, 43 (16.0%) hemorrhagic, and 15 (5.6%) other. Disagreements occurred on 16% of initial adjudication of events. Using results from imaging, the number with TIA decreased by 8.6% and with ischemic stroke increased by 4.1%. Using less strict criteria to classify ischemic stroke subtypes reduced the number classified as undetermined, from 137 to 59, and numbers classified as cardioembolic and small vessel doubled. <b><i>Conclusions:</i></b> We hope that this work will motivate and facilitate investigators to use MESA data to investigate issues concerning TIA and stroke and will inform investigators seeking to adjudicate TIA and stroke in other studies

Supplementary Material for: Cognition and Incident Dementia Hospitalization: Results from the Atherosclerosis Risk in Communities Study

<b><i>Background/Aims:</i></b> Cognitive decline is a defining feature of dementia. We sought to determine if a single baseline cognitive test score or change in test score over time is more strongly associated with risk of dementia hospitalization. We also sought to compare short- and long-term dementia risk. <b><i>Methods:</i></b> Prospective cohort study of 9,399 individuals from the Atherosclerosis Risk in Communities Study (median 10 years of follow-up). Cognition was assessed at two time points (6 years apart) using three tests: Delayed Word Recall Test (DWRT), Digit Symbol Substitution Test (DSST), and Word Fluency Test. Dementia hospitalizations were determined using ICD-9 codes. <b><i>Results:</i></b> Baseline cognitive test scores were associated with both short-term and long-term risk of dementia. The association of 6-year change in cognitive test score with dementia risk was stronger than that of individual test scores at a single visit [change from highest to lowest tertile, DWRT: hazard ratio = 6.45 (95% confidence interval = 1.80–23.08); DSST: hazard ratio = 10.94 (95% confidence interval = 3.07–38.97)]. <b><i>Conclusions:</i></b> In this community-based population, 6-year changes in cognitive scores were more strongly associated with risk of incident dementia hospitalization than baseline scores, although single DWRT and DSST scores were predictive. Our findings support the contention that cognitive changes may precede clinical dementia by a decade or more

Supplementary Material for: Occupation, Retirement Age, and 20-Year Cognitive Decline: The Atherosclerosis Risk in Communities Neurocognitive Study

Introduction: We examined the association of both midlife occupation and age at retirement with cognitive decline in the Atherosclerosis Risk in Communities (ARIC) biracial community-based cohort. Methods: Current or most recent occupation at ARIC baseline (1987-89; ages 45-64y) was categorized based on 1980 US census major occupation groups and tertiles of the Nam-Powers-Boyd occupational status score (n=14,090). Retirement status via annual follow-up questionnaires administered ascertained in 1999-2007 was classified as occurring before or after age 70 (n=7,503). Generalized estimating equation models were used to examine associations of occupation and age at retirement with trajectories of global cognitive factor scores, assessed from visit 2 (1990-92) to visit 5 (2011–2013). Models were a priori stratified by race and sex and adjusted for demographics and comorbidities. Results: Low occupational status and blue-collar occupations were associated with low baseline cognitive scores in all race-sex strata. Low occupational status and homemaker status were associated with faster decline in White women but slower decline in Black women compared to high occupational status. Retirement before age 70 was associated with slower cognitive decline in White men and women and in Black men. Results did not change substantially after accounting for attrition. Conclusion: Low occupational status was associated with cognitive decline in women but not in men. Earlier retirement was associated with a slower cognitive decline in White participants and in Black men. Further research should explore reasons for the observed associations and race-sex differences

Supplementary Material for: Serum Vitamin D Concentrations and Cognitive Change Over 20 Years: The Atherosclerosis Risk in Communities Neurocognitive Study

<b><i>Background/Aims:</i></b> 25-hydroxyvitamin D (25[OH]D) concentrations have been associated with cognitive decline and incident dementia in elderly populations; however, these relationships are susceptible to reverse causation. Less is known about the association of midlife 25(OH)D with long-term cognitive decline. <b><i>Methods:</i></b> This was a prospective cohort study of 13,044 participants (mean age 57 years at baseline) in the Atherosclerosis Risk in Communities Study. 25(OH)D was measured from serum collected at baseline (1990–1992) using liquid chromatography tandem high-sensitivity mass spectrometry. Cognition was assessed using 3 neuropsychological tests at 3 time points, which were combined into a composite cognitive <i>Z</i>-score. Multivariable-adjusted linear mixed-effects models with random intercepts and slopes were used to estimate associations between 25(OH)D and cognitive change over 20 years. <b><i>Results:</i></b> Compared to persons with sufficient 25(OH)D (≥30 ng/mL), those with deficient (< 20 ng/mL) and intermediate (20–< 30 ng/mL) 25(OH)D concentrations had similar cognitive decline in composite cognitive <i>Z</i>-scores (deficient versus sufficient: –0.035 [95% CI –0.104 to 0.033] and intermediate versus sufficient: –0.029 [95% CI –0.080 to 0.023]). <b><i>Conclusions:</i></b> Lower concentrations of 25(OH)D measured in midlife were not significantly associated with more rapid cognitive decline over a 20-year follow-up period. The results of this prospective study are less susceptible to reverse causation than prior studies