Iran Smell Identification Test (Iran-SIT): a Modified Version of the University of Pennsylvania Smell Identification Test (UPSIT) for Iranian Population

Abstract

Introduction: Based on cultural adaption, various types of olfactory tests have been designed in different countries. The aim of this study was to develop a standardized smell identification test to evaluate the olfactory function of Iranian population. Methods: For designing Iran smell identification test (Iran-SIT), we selected the most familiar odors for Iranians, and prepared a 24-item smell identification test in four-alternative forced-choice paradigm. We tested 577 healthy subjects aged 6 to 68 years by Iran-SIT. In order to assess the reliability and stability of Iran-SIT over time, 96 subjects participated in the retest study after 5 months. Results: All odors of Iran-SIT were identified by more than 70 % of subjects. Identification scores were significantly changed by age. Children and elderly subjects represented significantly lower identification scores than adult aged 20–50 years. There were no significant differences between adult aged 20–50 years. Test-retest study revealed that Iran-SIT is a highly reliable and valid test (Pearson’s correlation coefficient between test-retest identification scores: r = 0.93). In order to classify adult patients into four olfactory disorder levels, we determined diagnostic criterion of olfactory disorder using Iran-SIT based on the identification score obtained from subjects aged 20–50 years. Conclusions: Iran-SIT with high reliability and validity has adequacy to distinguish among normosmia, mild microsmia, severe microsmia, and anosmia.