Predicting Pre-dementia

The goal of this observational study is to learn how well a multimodal "Progression and Risk" (PR) model can predict and stage early mild cognitive impairment (MCI) due to Alzheimer's disease in cognitively normal or very mildly impaired ApoE4-positive adults aged 55 and older. The main questions it aims to answer are: Can a prespecified proteogenomic PR model accurately predict conversion from cognitively normal (CN) or very mildly impaired status to pTau217-positive MCI Stage I within 24 months in ApoE4-positive adults? Does adding digital monitoring features (e.g., sleep, activity, speech), EMR-lifestyle risk scores, and plasma biomarkers to a polygenic risk score (PRS) meaningfully improve risk stratification and time-to-conversion prediction compared with simpler models (e.g., PRS alone or standard clinical risk factors)? If there is a comparison group: Researchers will compare performance of the full multimodal PR model (integrating PRS, plasma proteomics and other omics, digital monitoring, and EMR-lifestyle data) with simpler or reduced models (for example, PRS-only, biomarker-only, or models without continuous digital monitoring) to see if the full model provides higher discrimination (AUC/ROC), better calibration, and improved time-to-conversion prediction for CN to pTau217-positive MCI transitions. Participants will: Provide prior genomic data (ApoE genotype and whole-genome sequencing or high-density genotyping array data) for calculation of an ancestry- and sex-normalized Alzheimer's disease PRS and assignment to PRS-based risk strata. Attend an in-person baseline visit and follow-up visits at months 6, 12, 18, and 24 (±2 months) for clinical evaluation, neurocognitive testing (including CDR and digital cognitive batteries), and venous or capillary blood collection for plasma pTau217 and other AD biomarkers, proteomic and methylome panels, and routine safety labs when indicated. Use digital devices (e.g., Oura Ring and smartphone-based tools) for