P4‐339: EXCESS COSTS ASSOCIATED WITH POSSIBLE MISDIAGNOSIS OF ALZHEIMER'S DISEASE AMONG PATIENTS WITH VASCULAR DEMENTIA IN A UK CPRD POPULATION. (1st July 2014) - Happich, Michael; Kirson, Noam Y.; Desai, Urvi; King, Sarah; Birnbaum, Howard G.; Price, David; Belger, Mark; Hunter, Craig A.; Lenox‐Smith, Alan J.; Reed, Catherine C.