The diagnostic pathway of Alzheimer's disease in real-world clinical practice in Spain: results from the Adelphi Dementia Disease Specific Programme™

Pascual Sánchez-Juan^1,2Pablo Baz³Enrique Arrieta⁴Diego Novick⁵Silvia Díaz-Cerezo⁶Sarah Cotton⁷Chloe Walker⁷Ángel Trueba⁶Mercedes Núñez^6*

• ¹Instituto de Salud Carlos III, Madrid, Spain
• ²Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
• ³Centro de Salud Periurbana Norte, Salamanca, Spain
• ⁴Centro de Salud Segovia Rural, Segovia, Spain
• ⁵Eli Lilly & Company, Arlington, United Kingdom
• ⁶Eli Lilly & Company, Alcobendas, Madrid, Spain
• ⁷Adelphi Real World, Bollington, United Kingdom

Introduction: There are challenges associated with the timely diagnosis of people with mild cognitive impairment (MCI) and Alzheimer's disease (AD), especially with the future introduction of amyloid-targeting therapies. This study evaluates the current diagnostic journey for MCI and dementia due to AD in Spain. Methods: This study used data from the Adelphi Real World Dementia Disease Specific Programme (DSPTM), a cross-sectional survey with retrospective data collection. The survey involved primary care physicians (PCPs) and hospital specialists with experience in managing and treating AD, along with their consulting patients, between January and July 2023 in Spain. Analyses were descriptive. Results: Physicians (N=94; 44.7% PCPs, 38.3% neurologists) reported data for 723 patients. Most patients (78.9%) first consulted a PCP. The median (inter-quartile range) time since symptom onset to first consultation was 21.6 (6.1–48.2) weeks and, in those patients who were not diagnosed immediately, the time from first consultation to diagnosis was 13.0 (6.0-21.9) weeks if diagnosed by a PCP, or 28.9 (17.1-52.1) weeks if diagnosed by specialist. The diagnosing physician was a specialist or a PCP for 83.2% and 16.8% of patients, respectively. In addition, the most used advanced diagnostic technics were computed tomography scans and magnetic resonance imaging (57.2% and 43.3% of patients, respectively). CSF determination of AD biomarkers was conducted in 12.4% of patients and AD-specific blood biomarkers in 2.9%. Treatment was mostly initiated by neurologists. Conclusion: The diagnostic process for people with MCI and AD could be accelerated by increased awareness of the disease, shorter referral times, and better access to specialized diagnostic services. This study shows limited use of AD-specific biomarker testing in Spain.