Cross-cultural Validation: Sniffin’ Sticks Olfactory Test for Threshold, Discrimination, and Identification in Spanish-speaking Cohorts

Abstract

The assessment of olfactory function is increasingly pertinent, particularly in cases of cognitive decline, where olfactory changes might serve as early biomarkers. The Sniffin’ Sticks Olfactory Test, validated internationally, offers an objective measure of olfactory performance. Olfactory testing is comprised of three different components: olfactory threshold, odor discrimination, and odor identification. The Sniffin’ Sticks Olfactory Test is an optimal performance test that evaluates these three components of olfaction to generate a composite score resulting from the summation of threshold, discrimination, and identification. This study sought to validate the test in a Spanish cohort. The normative sample comprised 209 healthy normosmic volunteers (154 females, 55 males), aged 20 to 79 years (mean age = 50.11 ± 15.18 years). Additionally, 22 participants were retested for test-retest reliability, and odor familiarity in the olfactory identification test was explored in an independent healthy sample (n = 69), necessitating cultural adaptations. The findings revealed comparable performance between genders and smokers/non-smokers across all tests. However, significant intergroup differences emerged in scores across age brackets. Notably, olfactory function exhibited a progressive decline with age, with individuals over 60 years displaying the lowest scores. This comprehensive dataset, coupled with culturally tailored adjustments, enables the administration of the Sniffin’ Sticks Olfactory Test within the Spanish population. In summary, our study underscores the applicability of the Sniffin’ Sticks Olfactory Test in Spain. This tool's validation, coupled with insights into cultural nuances and normative data, provides a robust foundation for its implementation, facilitating accurate olfactory assessments in Spanish individuals across various age groups.