Assessment of olfaction using the "i-smell" test in an Indian population: a pilot study

The objective of our study was to assess the olfactory function in patients having sinonasal disease and in normal healthy individuals and to establish a clinical test for olfaction in Indian population. Odor threshold and odor identification testing in patients of sinonasal disease and in subjects with no sinonasal disease was done in an academic tertiary medical center. Fifty patients with sinonasal disease (Group A) and 100 normal subjects with no complaints of olfactory dysfunction (Group B) were prospectively recruited. Group A was evaluated using visual analogue scales for subjective grading of olfactory function, nasal endoscopy and odor threshold and identification abilities. Group B was evaluated using nasal endoscopy and combined olfactory score. The combined olfactory score (COS) in group A ranged from 0 to 15 (mean 7.85, SD 2.26). The score in group B ranged from 7 to 19 (mean 14.57, SD 4.78). Statistically significant correlation was observed between VAS and COS (r = 0.764, p < 0.001) and nasal endoscopy score and COS (r = 0.55, p < 0.001) in group A. The "I-Smell" test could effectively discriminate between subjects with olfactory dysfunction and the normosmic subjects and is feasible to be used in Indian population.