P1‐333: DETECTING CLINICALLY RELEVANT CHANGES IN DEMENTIA USING INSTRUMENTAL ACTIVITIES OF DAILY LIVING: A LONGITUDINAL VALIDATION STUDY WITH 3, 6, 9 AND 12 MONTHS FOLLOW‐UP. (1st July 2006) - Verrijp, Merike; Dubbelman, Mark A.; Jutten, Roos J.; Beker, Nina; Wesselman, Linda M.P.; Sikkes, Sietske A.M.; Scheltens, Philip