Comparison of subjective olfaction ratings in patients with and without olfactory disorders

Objective: Olfactory dysfunction is common. The reliability of self-assessment tools for smell testing is still controversial. This study aimed to provide new data about the accuracy of olfactory self-assessment compared with a standardised smell test. Design: Prospective, controlled, cohort study of patients with olfactory disorders and healthy controls. Subjects: Ninety-six patients with a smell deficit and 71 controls were asked to rate their sense of smell on a visual analogue scale. Their olfactory abilities were also evaluated with the Sniffin' Sticks tests. Results: The whole cohort showed a significant correlation between visual analogue scale smell scores and Sniffin' Sticks total scores. This correlation was also significant in the patient group, but not in the control group. These results were independent of olfactory deficit aetiology and subject age. Conclusion: Self-assessment of olfaction is only a reliable indicator in smell-impaired patients, not in healthy controls. For an accurate assessment of olfaction, reliable, standardised tests are needed.