Number of Descriptors in Cued Odor Identification Tests

OBJECTIVE: To investigate whether results from cued odor identification tests are influenced by the number of verbal descriptors presented with each odor and whether a larger number of descriptors would improve the differentiation between individuals with various degrees of olfactory loss. DESIGN: Randomized, crossover study. SETTING: University Clinic in Brussels. PARTICIPANTS: Two hundred thirty-eight study participants (128 with olfactory concerns and 110 control individuals without such concerns). The study took place from March 1, 2008, to April 30, 2009. MAIN OUTCOME MEASURES: Results of the 3-alternative forced choice (AFC) and 6-AFC identification tests, which consisted of 32 odor items each. RESULTS: A high correlation was found between the results obtained with the 2 tests. Although no sex-related differences were present, age was found to interact with performance in that lower test scores were obtained for older participants with the 6-AFC test, compared with the 3-AFC test. Of the 2 tests, the 6-AFC better separated participants with self-assessed olfactory deficits from participants without such concerns. It also discriminated more strongly between posttraumatic and postviral and sinonasal underlying causes of olfactory loss. CONCLUSIONS: Cued odor identification tests with various numbers of verbal descriptors produce similar results. However, an increasing number of alternative descriptive items seem to allow for better discrimination between individuals with and without olfactory loss.