Factor structure of the Harmonized Cognitive Assessment Protocol neuropsychological battery in the Health and Retirement Study

Objectives: The Harmonized Cognitive Assessment Protocol (HCAP) describes an assessment battery and a family of population-representative studies measuring neuropsychological performance. We describe the factorial structure of the HCAP battery in the US Health and Retirement Study (HRS).Method: The HCAP battery was compiled from existing measures by a cross-disciplinary and international panel of researchers. The HCAP battery used in the 2016 wave of the HRS. We used factor analysis methods to assess and refine a theoretically-driven single and multiple domain factor structure for tests included in the HCAP battery among 3,347 participants with evaluable performance data. Results: For the eight domains of cognitive functioning identified theoretically (orientation, memory [immediate, delayed, & recognition], set shifting, attention/speed, language/fluency, andvisuospatial), all single factor models fit reasonably well, although four of these domains had either 2 or 3 indicators where good fit is axiomatic. Multidimensional models suggested the eight-domain model was overly complex. A five-domain model (orientation, memory delayed and recognition, executive functioning, language/fluency, visuospatial) was identified as a reasonable model for summarizing performance in this sample (standardized root mean square residual = 0.05, root mean square error of approximation = 0.05, confirmatory fit index = 0.94). Discussion: The HCAP battery conforms adequately to a multidimensional structure of neuropsychological performance. The derived measurement models can be used as anchors for calibrating cross-national studies of cognitive performance, and to identify persons performing atthe low end as part of an algorithmic classification of probable dementia