Skip to main content
Fig. 1 | Alzheimer's Research & Therapy

Fig. 1

From: Cost-effectiveness of cerebrospinal biomarkers for the diagnosis of Alzheimer’s disease

Fig. 1

Patient cohort and decision model. a Flowchart of patients referred to a memory clinic or neurology practice with suspected dementia, some of whom would be diagnosed with probable AD after clinical assessment and MRI. If MRI does not provide a definitive non-AD diagnosis for any patients, and if all patients remain candidates for biomarker analysis, the pretest prevalence of AD is 12.7%. If MRI provides a definitive non-AD diagnosis for some patients, the pretest prevalence of AD in the cohort patients who continue to have suspected AD is greater than 12.7%. b Schematic of a decision tree. The blue square represents the decision whether to use CSF biomarkers. Green circles represent chance events. The population is divided into four groups on the basis of whether the patients have Alzheimer’s disease and the outcome of the diagnostic strategy: true-positive, false-negative, false-positive, and true-negative. The proportion of patients in each group is determined by the prevalence of AD in the evaluated cohort and the sensitivity and specificity of each diagnostic strategy. c Markov model of Alzheimer’s disease. Patients begin in the health states for community-dwelling mild, moderate, and severe AD. Each month, patients may die, progress or regress in terms of disease severity, discontinue or reinitiate treatment, transition from living in the community to living in a long-term care facility, or stay in the same health state. In the model, patients living in a long-term care facility cannot return to living in the community. d Markov model for patients with non-AD dementia. Patients begin in the community-dwelling non-AD dementia state. Only those with a false-positive diagnosis of AD receive AD treatment. Each month, patients may die, discontinue or reinitiate treatment, transition from living in the community to living in a long-term care facility, or stay in the same health state. AD Alzheimer’s disease, BM Biomarker, CSF Cerebrospinal fluid, MRI Magnetic resonance imaging, MTL Medial temporal lobe, SN Sensitivity, SP Specificity

Back to article page