Cognitive domain harmonization and cocalibration in studies of older adults.

Abstract

Objective: Studies use different instruments to measure cognitirating cognitive tests permit direct comparisons of individuals across studies and pooling data for joint analyses. Method: We began our legacy item bank with data from the Adult Changes in Thought study (n = 5,546), the Alzheimer's Disease Neuroimaging Initiative (n = 3,016), the Rush Memory and Aging Project (n = 2,163), and the Religious on such as the Mini-Mental State Examination, the Alzheimer's Disease Assessment Scale-Cognitive Subscale, the Wechsler Memory Scale, and the Boston Naming Test. CocalibOrders Study (n = 1,456). Our workflow begins with categorizing items administered in each study as indicators of memory, executive functioning, language, visuospatial functioning, or none of these domains. We use confirmatory factor analysis models with data from the most recent visit on the pooled sample across these four studies for cocalibration and derive item parameters for all items. Using these item parameters, we then estimate factor scores along with corresponding standard errors for each domain for each study. We added additional studies to our pipeline as available and focused on thorough consideration of candidate anchor items with identical content and administration methods across studies. Results: Prestatistical harmonization steps such qualitative and quantitative assessment of granular cognitive items and evaluating factor structure are important steps when trying to cocalibrate cognitive scores across studies. We have cocalibrated cognitive data and derived scores for four domains for 76,723 individuals across 10 studies. Conclusions: We have implemented a large-scale effort to harmonize and cocalibrate cognitive domain scores across multiple studies of cognitive aging. Scores on the same metric This document is copyrighted by the American Psychological Association or one of its allied publishers.This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.

Ceiling effects and differential measurement precision across calibrated cognitive scores in the Framingham Study.

“…These scores can be used by investigators in conjunction with other rich data the FHS has collected over the more than 40 years of the study. Additionally, the methods we employed ensure that these scores are comparable to those from other studies we have calibrated, enabling direct cross-study comparisons (Mukherjee et al, 2022). Due to differences in items administered across time and cohorts it would have required strong and untenable assumptions to obtain Z -scores that were comparable across the different batteries in the FHS.…”

“…The aim of the precalibration step was to define the sample to be used at cocalibration and to determine whether data from the FHS were consistent with the models we used for calibrating the anchor items in our prior work, including the secondary domain structure inherited from analyses of prior studies. Details of how we identified secondary domains are provided in our companion article (Mukherjee et al, 2022). We only used NP and hybrid visits since these included responses to nonanchor items for which we needed to estimate item parameters.…”

“…In keeping with our previous harmonization work that focused on older populations (Mukherjee et al, 2022), we initially restricted to scoring visits where individuals were at least 60 years or older (older adult scores). The sample for the older adult scores is shown in Figure 2.…”

“…This is not an unusual consideration for long running cohort studies. Similar situations arise in, for example, Alzheimer’s Disease Research Center (ADRC) data where the combination of multiple versions of the uniform data set (UDS) along with center specific batteries leads to similarly complex data (Mukherjee et al, 2022).…”

Harmonization of neuropsychological and other clinical endpoints: Pitfalls and possibilities.

“…• Mukherjee et al (2022) describe the workflow they established for the prestatistical harmonization of cognitive domain scores across multiple aging studies through the co-calibration of items in an item bank based on confirmatory factor analysis.…”