q-Powders: a quick test for screening retronasal olfactory disorders with tasteless powders

Abstract

Purpose To investigate the clinical utility of q-Powders—a retronasal identification screening test. Methods A total of 156 subjects (92 females, mean age: 54.5 years ± 17.3 years) completed a 3-item q-Powders retronasal identification test and a 16-items Sniffin’ Sticks orthonasal identification test. We analyzed whether the q-Powders test could differentiate between subjects with normosmia and subjects with an olfactory disorder. Results Our data indicated that subjects with an olfactory disorder scored lower in the q-Powders test than subjects with normosmia. The analyses revealed q-Powders test sensitivity of 84% and a test specificity of 64.9% with a score of 2 points taken as a cutoff for olfactory disorders. Conclusion The 3-item q-Powders retronasal test may be used for screening purposes in clinical research. Level of evidence 4

Correlations between gustatory, trigeminal, and olfactory functions and nasal airflow

“…The q-powders test [ 19 ] comprised three odors (cinnamon, banana, garlic; Givaudan Schweiz AG, Dubendorf, Switzerland). Participants were asked to choose which among the 6 descriptors, presented as flash cards, best describes the flavor of each of the powders.…”

“…The odors were selected based on results from previous studies where the identification rates of the 3 selected odors were high (> 95%) [ 25 ]. The highest score is 3, a score of 0 may be interpreted as anosmia, while 1 or 2 would mean that further testing is required [ 19 ].…”

“…This study aimed to determine the relationship of olfaction, gustation, trigeminal function, and nasal airflow with each other in individuals without chemosensory complaints. Due to the large sample we aimed to test, we decided to use peak nasal inspiratory flow (PNIF, nasal airflow) and various chemosensory screening tests (q-sticks (orthonasal olfaction) [ 18 ], q-powders (retronasal olfaction) [ 19 ], trigeminal lateralization (trigeminal function) [ 20 ], and taste sprays (whole mouth gustation) [ 21 ]) to measure function. In addition, the study aimed to determine whether self-ratings (measured using visual analogue scales, VAS) for smell ability, taste ability, and nasal airflow, composite sinusitis symptom scores, significance of olfaction questionnaire scores, or other patient-related factors are related to the outcomes of these screening tests.…”

Gustatory event-related potential alterations in olfactory dysfunction patients

“…However, those researches on the influences of smell on taste were mostly based on psychophysical chemical tests and functional imaging examinations. In psychophysical chemical tests, impaired olfactory function, especially the retro-nasal smell produced by volatile agents dissolved in the mouth by chewing and saliva, was usually roughly reported as changes in "taste perception" by subjects can lead to data distortion [14,15]. The utility of functional imaging examinations was restricted by the delayed cortical response to the taste stimuli and unclear brain positioning.…”