Evaluation of odor recognition threshold measurement methods in T&T olfactometry: A survey study

Kei Hosoya; Taro Komachi; Yohei Maeda; Hitoshi Akazawa; Eriko Ogino; Azusa Yoshida; Kimihiro Okubo; Takaki Miwa

doi:10.1016/j.anl.2023.07.009

Evaluation of odor recognition threshold measurement methods in T&T olfactometry: A survey study

Auris Nasus Larynx. 2024 Feb;51(1):61-68. doi: 10.1016/j.anl.2023.07.009. Epub 2023 Aug 11.

Authors

Kei Hosoya¹, Taro Komachi², Yohei Maeda³, Hitoshi Akazawa⁴, Eriko Ogino⁵, Azusa Yoshida⁶, Kimihiro Okubo⁷, Takaki Miwa⁸

Affiliations

¹ Department of Otolaryngology, Nippon Medical School, Musashi Kosugi Hospital, Kanagawa, Japan. Electronic address: s00-073@nms.ac.jp.
² Department of Otolaryngology, Nippon Medical School, Chiba Hokusoh Hospital, Chiba, Japan.
³ Department of Otorhinolaryngology, Japan Community Heath Care Organization Osaka Hospital, Osaka, Japan; Department of Otolaryngology-Head and Neck Surgery, Sakai City Medical Center, Osaka, Japan.
⁴ Department of Otolaryngology, Sakai City Medical Center, Osaka, Japan.
⁵ Kyoto Nose and Allergy Clinic, Kyoto, Japan.
⁶ Department of Clinical Laboratory Center, Nippon Medical School, Tama Nagayama Hospital, Tokyo, Japan.
⁷ Department of Otolaryngology, Head and Neck Surgery, Nippon Medical School Hospital, Tokyo, Japan.
⁸ Department of Otorhinolaryngology, Kanazawa Medical University, Kanazawa, Japan.

PMID: 37574422
DOI: 10.1016/j.anl.2023.07.009

Abstract

Objective: The odor recognition thresholds in T&T olfactometry are measured by either the examiner's judgment of the patients' odor expression for each standard odor or by the patient's choice of the correct response from an olfactory term table. This study aimed to clarify the correct odor expressions and use of the olfactory term table.

Methods: A questionnaire was administered to otolaryngologists or medical staff in charge of testing at facilities where T&T olfactometry is performed. The questionnaire consisted of the facility's background, environment and procedures of T&T olfactometry, choice of the correct answer with five different standard odors, and use of the olfactory term table. For the choices, the expressions used were those considered correct at Nippon Medical School Tama Nagayama Hospital and the Kyoto Nose and Allergy Clinic.

Results: A total of 81 valid responses were obtained. Most respondents belonged to medical and educational institutions (59.3%, 48/81). The laboratories in the respondents' institutions were completely ventilated using various methods. Clinical laboratory technicians inspected 51.7% (45/81) of the facilities. The order of standard odors in the odor recognition threshold test differs depending on the facility. When the examiner was unsure about the answer given by the patient in the odor recognition threshold test, 16.1% (9/56) of the respondents chose "present the olfactory term table," 33.9% (19/56) chose "increase the concentration," and 37.5% (21/56) chose "present the olfactory term table" or "increase the concentration," depending on the situation. A total of 96.4% (54/56) of the facilities treated odor expressions other than those in the olfactory term table as correct, and the odor expressions that were considered correct differed from facility to facility. Of the respondents, 80.2% (65/81) answered "I know the olfactory term table," and the mean value of satisfaction with the current olfactory term table was 4.4 ± 3.0. Of the respondents, 81.5% (53/65) answered that "the timing of presenting the olfactory term table should be standardized in all facilities."

Conclusion: In the odor recognition threshold test by T&T olfactometry, this study revealed that the odor expressions considered as correct answers for the standard odors and the use of the olfactory term table differed among facilities.

Keywords: Olfactory dysfunction; Olfactory term table; Recognition threshold; Standard odors; Survey; T&T olfactometry.

MeSH terms

Humans
Odorants*
Olfactometry
Smell* / physiology