The Influence of Distractors on Odor Identification

Objective: To investigate the impact of the use of more contrasted distractors on correct odor identification in patients with olfactory loss. Design: Randomized, cross-over study. Setting: University clinic. Patients: Thirty patients with olfactory deficits. Interventions: The olfactory function of the patients was evaluated by means of the Sniffin' Sticks test battery. Main Outcome Measures: The distractors of the Sniffin' Sticks odor identification test (classic test) were modified, and more contrasted distractors were used (contrasted test), while the applied odorants were the same. All patients performed both the classic and the contrasted odor identification tests in a randomized sequence. Results: Eighteen patients were hyposmic, and 12 were functionally anosmic. Odor identification was significantly better in the hyposmic patients than in the anosmic patients (P<.01). As predicted, hyposmic patients demonstrated a significant increase in correct odor identification in the contrasted test, while anosmic patients did not. Conclusion: The use of more contrasted distractors in cued odor identification tasks can contribute to better discrimination of anosmic and hyposmic patients, which is highly valuable in a clinical context.