Correlation between olfactory severity ratings based on olfactory function test scores and self-reported severity rating of olfactory loss

Acta Otolaryngol. 2017 Jul;137(7):750-754. doi: 10.1080/00016489.2016.1277782. Epub 2017 Jan 23.


Conclusion: Olfactory test scores are significantly correlated with self-rated severity scales. However, the statistical rating based on olfactory tests did not strongly agree with the self-reported severity rating. This suggests that there is a discrepancy between olfactory test results and the severity described by patients themselves.

Objectives: This study aimed to identify the correlation between statistical ratings based on test scores and self-rating of the severity of olfactory loss.

Method: A total of 1555 subjects were asked to rate olfactory loss severity by one of five scales. Olfactory tests consist of the butanol threshold test (BTT) and cross-cultural smell identification test (CCSIT).

Results: There were significant correlations between BTT scores and self-rated severity scales (r = 0.619, p < 0.001) and between CCSIT scores and self-rated severity scales (r = 0.597, p < 0.001) after adjustment for age, sex, and medical conditions. Using discriminant analysis for both BTT and CCSIT, scores 0-4 could be statistically rated as anosmia, scores 5 and 6 as severe hyposmia, scores 7 and 8 as moderate hyposmia, and scores 9-12 as normosmia (Wilks's lambda = 0.605, p < 0.001 for BTT and Wilks's lambda = 0.597, p < 0.001 for CCSIT).

Keywords: Anosmia; BTT; CCSIT; butanol threshold test; correlation; cross-cultural smell identification test; hyposmia; loss of smell; olfactory function.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Humans
  • Male
  • Middle Aged
  • Olfaction Disorders / diagnosis*
  • Severity of Illness Index*
  • Young Adult