Affiliations: [a] Evaluation Unit of the Canary Islands Health Service (SESCS), Tenerife, Spain | [b] Canary Islands Foundation for Health and Research (FUNCIS), Tenerife, Spain | [c] Health Services Research on Chronic Patients Network (REDISSEC), Spain | [d] Alzheimer's disease and other cognitive disorders unit. IDIBAPS, Hospital Clinic, Barcelona, Spain | [e] Clinical Management Service, Alto Deba Hospital, Mondragon, Spain | [f] Centre for Biomedical Research of the Canary Islands (CIBICAN), La Laguna, Spain
Correspondence:
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Correspondence to: Cristina Valcárcel-Nazco, Servicio de Evaluación del Servicio Canario de la Salud (SESCS), Camino Candelaria, 44, 38109 El Rosario, Santa Cruz de Tenerife, Canary Islands, Spain. Tel.: +34 922 68 40 19; E-mail: cristina.valcarcelnazco@sescs.es.
Abstract: Background:The use of cerebrospinal fluid (CSF) biomarkers could facilitate early detection of Alzheimer’s disease (AD) in patients with mild cognitive impairment (MCI) and the differential diagnosis between AD and non-AD dementias. Objective:To determine the cost-effectiveness of the use of amyloid-β peptide (Aβ42), total tau and phosphorylated tau proteins in CSF to diagnose AD in MCI and dementia patients. Methods:An economic evaluation was performed by means of cost-effectiveness analysis comparing two AD diagnostic alternatives: the combined determination of Aβ42 proteins, total tau and phosphorylated tau in CSF as biomarkers of AD, and the standard clinical diagnosis based on the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer’s Disease and Related Disorders Association (NINDS-ADRDA) criteria. A decision analytic model was developed to synthesize the identified evidence and to compare the costs and effectiveness associated with each diagnostic strategy. A probabilistic sensitivity analysis using 2nd order Monte Carlo simulations was performed. Subsequently, acceptability curves were calculated and ANCOVA models were applied to the results of the Monte Carlo simulations in order to identify the parameters that led greater variability in the model outcomes. Results:The use of CSF biomarkers as an early diagnostic strategy of AD in MCI patients is a dominant alternative (less costly and more effective strategy than standard clinical diagnostic criteria). In dementia patients, although there is a higher uncertainty, biomarkers in CSF seem a more cost-effective alternative than standard clinical diagnostic criteria. Conclusions:Detecting AD in MCI patients by determining Aβ42, total tau and phosphorylated tau proteins biomarkers in CSF is a cost-effective diagnostic alternative. No conclusive results were obtained on dementia patients.
Keywords: Alzheimer's disease, amyloid-β, biomarkers, cost-effectiveness, diagnosis, phosphorylated tau, total tau
