qU-Sniff - the development of a short version of the Universal "Sniffin' Sticks" test

Objectives: Extensive olfactory testing is sparsely applied in pediatric patients in clinical routine especially because of its time taking nature. Therefore a 5-item odor identification test (quick "U-Sniff", "qU-Sniff") from the 12-item "U-Sniff" test was developed. Methods: A total of 724 normosmic children between 6 and 17 years of age, divided in four age groups, were included in this retrospective study. Additionally, 17 children with congenital anosmia in the same age range were included. To calculate test-retest reliability 90 participants from the healthy group were tested twice. Results: The five most correctly identified odors from the 12-item "U-Sniff" test were: coffee (98 %), peach (95 %), flower (90 %), fish (88 %) and onion (84 %). Normosmic participants scored 4.71 +/- 0.62 points on the "qU-Sniff" test. A significant correlation between results of the 12-item and 5-item test (n = 724; r(s) = 0.580; p < 0.001) and a significant test-retest reliability (r(s) = 0.626, p < 0.001) were shown. For "qU-Sniff" validation a ROC analysis to distinguish between anosmic patients and healthy controls was conducted for each age group separately. AUCs were as followed: i) 0.963 +/- 0.018, p < 0,001; ii) 0.978 +/- 0.013, p < 0.001; iii) 0.992 +/- 0.006, p < 0.001; iv) 0.994 +/- 0.005, p < 0.001. The cut-off value to determine anosmic and normosmic participants was <4 points. Conclusion: With the "qU-Sniff" test, we present a short screening tool for clinical routine with <4 points as cut-off to initiate more detailed olfactory testing.