Cognitive Assessment and Adjudication Core

The goal of the Cognitive Assessment and Adjudication Core (Cognition Core) of the Diabetes Prevention Program Outcomes Study (DPPOS) Alzheimer’s disease (AD) and AD related dementias (ADRD) project is to conduct all training, certification, quality assurance (QA) and quality control (QC) activities related to cognitive testing and collection of data necessary to measure cognitive decline and define the cognitive syndromes of mild cognitive impairment (MCI) and dementia. In addition, the Cognition Core will work with the Neuroimaging and Plasma Biomarkers core (Biomarkers Core) and the DPPOS Clinical Operations and Procedures Core (Clinical Core) to further classify cognitive decline, MCI, and dementia as due to AD continuum, non-AD pathologic change, or vascular contributions to cognitive impairment and dementia (VCID), and with the Biostatistics and Data Infrastructure Core (Data Core) in analyses of cognitive data and their interpretation. DPPOS has included the Spanish English Verbal Learning Test (SEVLT), the Digit Symbol Substitution Test (DSST), since 2009. And the Modified Mini-Mental Status Exam (3MS) since 2015. We propose to continue using the SEVLT, DSST, and 3MS in the two proposed assessment waves, adding comprehensive cognitive and functional testing using the third version of the National Alzheimer’s Coordinating Center (NACC) uniform dataset (UDS) forms. The cognition core will achieve its goal through the following aims: (1) To develop, maintain, update, and implement training, certification, and QA procedures related to cognitive and functional testing including training manuals, videos, and certification and recertification processes for the SEVLT, DSST, and 3MS, version 3 of the NACC- UDS cognitive, physician, and functional assessments; (2) To develop and implement QC procedures related to cognitive and functional testing including, central examination of testing forms and audio recordings from 10% of all tests administered on a quarterly basis, retraining and recertification of DPPOS site personnel as necessary, and continuous quality improvement through real time queries via email with a dedicated core manager; (3) To implement an adjudication procedure for the diagnoses of MCI, dementia, and their subtypes, including summary forms of cognitive and functional data to be evaluated by experienced cognitive adjudicators, a website for the distribution of the summary forms and entry of cognitive diagnoses by adjudicators, and a process for resolution of disagreements among adjudicators; (4) Further adjudicate MCI and dementia as AD continuum or non-AD pathology using plasma ptau-181 in all participants and amyloid positron emission tomography (PET) in those undergoing brain imaging, explore adjudicating VCID using cerebrovascular data from MRI, clinical brain imaging, and history of stroke, and explore the use of biomarkers of neurodegeneration and tau to define tau and neurodegeneration with and without amyloid positivity; (5) Assist the data core in the analyses of cognitive data for all projects; (6) Assist the Clinical Core in the return of cognitive diagnoses to study participants.