Alzheimer Disease Alzheimer disease Antibodies, Monoclonal, Humanized Article Clinical Dementia Rating Cost-Benefit Analysis Food and Drug Administration Humans Quality-Adjusted Life Years Treatment Outcome aducanumab amyloid beta protein amyloid plaque brain edema brain hemorrhage clinical effectiveness clinical outcome cognition confusion cost benefit analysis cost effectiveness analysis dementia diagnostic imaging dizziness drug approval drug cost drug efficacy drug megadose drug safety drug withdrawal