Digital adaptation of odor identification test: Current knowledge, gaps, and initial insights from a DAC global cohort.

Background: Olfaction has enabled humans to survive and reproduce throughout their evolutionary history. Certain odors have been historically associated with danger while others, pleasure. Further, olfactory impairment is one of the earliest manifestations of neurodegeneration, such as Alzheimer's disease. Therefore, olfactory tests have the potential to reveal insights into a person's brain health. The landscape of orthonasal olfactory tools is vast, and many have been adapted for populations living in low- and middle-income countries, but challenges remain in the awareness of the utility of olfactory testing, effective deployment, and scalability.

Objective: This report explores the current landscape of olfactory tests, the potential for digital tests to provide scalable data in low-resource settings, and their potential applicability in the Alzheimer's disease and brain health space. We also describe the ScentAware digital odor identification test and present some preliminary findings from its use in Egypt, a site for the Davos Alzheimer's Collaborative's Global Cohorts Program.

Methods: The American University in Cairo in partnership with University College London collected olfactory data using the ScentAware test from 125 participants from the North African Dementia Registry, a longitudinal study of community dwelling adults over age 55 in Egypt and the surrounding Middle East and North Africa region.

Results: Participants' olfactory function measured by the culturally adapted ScentAware test somewhat correlated with language and memory, as assessed by the Egyptian Harmonized Cognitive Assessment Protocol battery.

Conclusions: Our adaptation of the ScentAware test suggests that digital olfactory assessment holds promise for cost-effective deployment at scale in a low-resource setting.