A Quick Test to Objectify Smell and Taste Dysfunction at Home: a Proof-of-Concept for the Validation of the Chemosensory Perception Test

Abstract

Recent studies have shown the efficacy of a home test for the self-evaluation of olfactory and gustatory functions in quarantined COVID-19 patients. However, testing was often limited to COVID-19 participants, and the accuracy of home test kits was rarely compared to standardized testing. This study aims at providing proof-of-concept for the validation of the new Chemosensory Perception Test (CPT) developed to remotely assess orthonasal olfactory, retronasal olfactory and gustatory functions in various populations using common North American household items. In the two experiments, a total of 121 participants irrespective of having olfactory and/or gustatory complaints from various causes (COVID-19, sinunasal, post-viral, idiopathic) were tested first, with one/ many of the following tests: 1) a brief chemosensory questionnaire, 2) an olfactory test - Sniffin’Sticks Test (SST) or University of Pennsylvania Smell Identification Test (UPSIT) and/or 3) a gustatory test - Brief Waterless Empirical Taste Test (B-WETT). We then applied the CPT which yielded three different subscores, namely orthonasal, retronasal and gustatory CPT scores. The orthonasal CPT score was significantly correlated with SST (ρ=0.837, p<.001) and UPSIT (ρ=0.364, p<.001) scores, and exhibited an excellent accuracy to identify olfactory dysfunction as compared to SST (AUC: 0.923 [95% CI, 0.822-1.000], p<.001). The retronasal CPT score and not the gustatory CPT score, allowed to distinguish between participants with or without subjective gustatory complaint (AUC: 0.818 [95% CI, 0.726-0.909], p<.001). The Chemosensory Perception Test has the ability to identify olfactory dysfunction, and to quantify subjective gustatory complaints.