Robustness of CSF Aβ42/40 and Aβ42/P‐tau181 to detect AD related outcomes using fully automated immunoassays

An obstacle to the broad implementation of CSF AD biomarkers is the identification of uniform cutoffs and measurement variability that can result in diagnostic uncertainty at the patient level. We aimed to determine the comparability of cut‐offs for CSF immunoassays for Aβ42/Aβ40 and Aβ42/P‐tau181 and to assess the effects of variability in CSF measurements on AD‐related outcomes (Aβ‐PET visual read and progression from MCI to AD dementia).