University of Exeter Medical School (J.M.R., E.K., W.H., D.J.L.); Centre for Dementia Prevention, University of Edinburgh (G.M.-T.), United Kingdom; The Alan Turing Institute (D.J.L.), London, United Kingdom; and Medical School (K.M.L.), Institute for Social Research, Institute for Healthcare Policy and Innovation, Veterans Affairs Ann Arbor Healthcare System, University of Michigan.