P4‐641: A NOVEL APPROACH TO STUDY HEALTHCARE RESOURCE USE AND COSTS OF CARE AMONG MEDICARE‐ENROLLED PATIENTS DURING AND AFTER PARTICIPATING IN CLINICAL TRIALS FOR EARLY ALZHEIMER'S DISEASE. (1st July 2019) - Abbass, Ibrahim M.; Bonzani, Ian C.; Leung, Grace; Marques Assuncao, Sheila Seleri; Neumann, Peter J.; Fillit, Howard M.