Norming of the NIH Toolbox Cognition Battery Version 3

The NIH Toolbox^® for Assessment of Neurological and Behavioral Function Cognition Battery (NIHTB-CB) is a brief neuropsychological assessment tool created as part of the NIH Neuroscience Blueprint. Since its inception, NIHTB-CB has been widely used in a variety of clinical and research settings, including large-scale epidemiological studies. The NIHTB-CB was recently updated and re-normed to Version 3 (V3). We describe the approach to establish normative reference values. The NIHTB-CB tests were administered to a large English-speaking sample of n = 3,904 (average age = 25.7 years, 52.1% female) individuals from the U.S. population, stratified by age, race and ethnicity, sex assigned at birth, and education level within the four U.S. census regions. Normative data were raked via iterative proportional fitting (e.g., by sex assigned at birth, race, ethnicity, and educational attainment nested within geographic region) to derive sampling weights that match the demographic proportions from the U.S. Census targets. Through regression-based continuous norming and bootstrap techniques, age-adjusted and age-and-education-adjusted normative scores were created for individual measure-level and composite scores.