Costs of diagnosing early Alzheimer's disease in three European memory clinic settings: Results from the precision medicine in Alzheimer's disease project

Objectives: The implementation of disease-modifying treatments for Alzheimer's Disease (AD) will require cost-effective diagnostic processes. As part of The Precision Medicine In AD consortium (PMI-AD) project, the aim is to analyze the baseline costs of diagnosing early AD at memory clinics in Norway, Slovenia, and the Netherlands. Methods: The costs of cognitive testing and a clinical examination, apolipoprotein E, magnetic resonance imaging (MRI), cerebrospinal fluid (CSF), positron emission tomography and blood-based biomarkers (BBM), which are used in different combinations in the three countries, were analyzed. Standardized unit costs, adjusted for GDP per capita and based on Swedish conditions were applied. The costs were expressed in euros (<euro>) as of 2019. A diagnostic set comprising clinical examination, cognitive testing, MRI and CSF was defined as the gold standard, with MRI mainly used as an exclusion filter. Results: Cost data were available for 994 persons in Norway, 169 in Slovenia and 1015 in the Netherlands. The mean diagnostic costs were 1478 (95% confidence interval 1433-1523) <euro> in Norway, 851 (731-970) <euro> in Slovenia and 1184 (1135-1232) <euro> in the Netherlands. Norway had the highest unit costs but also the greatest use of tests. With a uniform diagnostic test set applied, the diagnostic costs were 1264 (1238-1291) <euro>, in Norway, 843 (771-914) <euro> in Slovenia and 1184 (1156-1213) <euro> in the Netherlands. There were no major cost differences between the final set of diagnoses. Conclusions: The total costs for setting a diagnosis of AD varied somewhat in the three countries, depending on unit costs and use of tests. These costs are relatively low in comparison to the societal costs of AD.