Validation of the Waterless Empirical Taste Test (WETT®)

Abstract

The sense of taste is rarely assessed quantitatively outside of a limited number of academic and industrial laboratories, despite its role in influencing nutrition, the flavor of foods and beverages, and protection against ingestion of spoiled and toxic foodstuffs. This dearth reflects, in part, practical limitations of most taste tests, most notably their reliance on liquid stimuli for stimulus presentation or rinsing. In this study, a novel portable taste test that requires neither liquid tastants nor liquid rinses is described and validated within a clinic population. This test, termed the Waterless Empirical Taste Test (WETT ® ), uses stimuli that are embedded in pads of monometer cellulose located on disposable plastic strips applied to the tongue's surface. The test-retest and split-half reliability coefficients of the WETT ® were 0.92 and 0.88, respectively. These respective coefficients for sucrose, NaCl, citric acid, caffeine, and MSG were 0.82 and 0.80, 0.78 and 0.77, 0.56 and 0.73, and 0.84 and 0.84. The WETT ® exhibited comparable, in some cases higher, sensitivity than two comparison taste tests, the Whole Mouth Taste Test and the Taste Quadrant Taste Test, to age, sex, etiology (head trauma vs. upper respiratory infections), and phenylthiocarbamide (PTC) taste ability. This study demonstrates that a taste test that does not require liquids can be as reliable and sensitive as more traditional liquid-based taste tests to clinical alterations in taste function.

Objective screening for olfactory and gustatory dysfunction during the COVID‐19 pandemic: A prospective study in healthcare workers using self‐administered testing

“…The Brief Smell Identification Test (B‐SIT) and the self‐administered version of the Waterless Empirical Taste Test (SA‐WETT®) were mailed, along with instructions for their self‐administration and scoring, to addresses provided by participants on the screening survey 16,17 …”

Comparison of Chinese and American subjects on the self‐administered Waterless Empirical Taste Test

“…We also found that such ability was greater in women than in men, regardless of their cultural background. These phenomena were also evidence in the clinical participants of the validation study of the WETT, where age and gender were significant factors for not only the WETT, but also for two chemically based taste tests (Doty et al, 2021 ). Again, however, the age‐related affect was attenuated for NaCl on all three tests.…”

“…The present study compared the performance of a sizable sample of Chinese and American subjects on a recently developed and very reliable taste test that employs, in addition to representatives of the four classic basic taste qualities, umami, a tastant that is more common in Chinese than in American cuisine (Doty, Wylie, & Potter, 2021 ). This test uses taste stimuli embedded in disposable pads of cellulose and has been found to be sensitive to age, sex, phenylthiocarbamide taster status, and head trauma.…”

Neuropsychiatric sequelae of long COVID-19: Pilot results from the COVID-19 neurological and molecular prospective cohort study in Georgia, USA

“…The UPSIT contains 40 multiple-choice questions involving the identification of microencapsulated odors to determine the degree of smell loss ( Doty et al, 1989 ). A Waterless Empirical Taste Test (WETT) was also given to the participant to be completed at home, which includes 27 taste strips with responses (sweet, sour, bitter, salty, brothy, or no taste) to assess taste quality and concentrations ( Doty et al, 2021 ). Once completed at home, both the UPSIT and WETT tests were scored by a researcher over the telephone or email.…”