AbstractBackgroundComposite scores may be useful to summarize overall language or visuospatial functioning. We generated composite scores for these domains from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) and evaluated their validity.MethodWe used item response theory to derive composite measures for language (ADNI‐Lan) and visuospatial functioning (ADNI‐VS). We performed multiple validation analyses comparing ADNI‐Lan and ADNI‐VS to individual test and global scores among participants with normal cognition (NC), mild cognitive impairment (MCI), and Alzheimer’s disease (AD). We evaluated ability to detect change, strength of association with a priori selected structural brain imaging findings, association with risk of AD conversion for people with MCI, and differences in intercepts and slopes for people with MCI with vs. without the CSF AD biomarker signature.ResultThere were 1,913 people with imaging data and age ³60. Single factor IRT models fit the data well for both composites. ADNI‐Lan outperformed MMSE language items, ADAS‐Cog language items, the Boston Naming Test (BNT), and fluency items in detecting change for MCI and AD. The clock score was modestly better than ADNI‐VS at detecting change for MCI and AD. ADNI Lan was the best at predicting MCI to AD conversion, while the clock score did slightly better than ADNI‐VS. Strength of association of language scores with structural MRI findings are shown in Table 1. ADNI‐Lan and the BNT had stronger associations than other scores for MCI in ADNI1, and also in ADNI2/ADNIGO except for BNT/temporal pole. For AD, ADNI‐Lan had strong associations with each region, similar to other scores except MMSE. Strength of association of visuospatial scores with structural MRI findings are shown in Table 2. ADNI‐VS and the clock had similar strong associations for most regions. People with MCI with the CSF AD biomarker signature had lower language intercepts, captured best by ADNI‐Lan, and more rapid decline, also captured best by ADNI‐Lan. Intercepts were not different for either visuospatial score, and ADNI‐VS and the clock score had similar slope terms.ConclusionADNI‐Lang and ADNI‐VS had good evidence of validity and may be useful composites for language and visuospatial functioning in ADNI.