The Correlation between Butanol Threshold Test (BTT) and Cross Cultural Smell Identification Test (CC-SIT) According to Causes of Olfactory Disorders

Background and ObjectivesZZOlfaction is a critical function of our body that allows one to avoid potential dangers in daily living. Although there are numerous subjective and objective tests evaluating the olfactory function, there exist no studies assessing correlations among such tests for various causes of olfactory dysfunction, especially in Korea. Subjects and MethodZZWe collected the olfactory functional test results of 473 subjects who visited our outpatient clinic. We categorized these patients into 5 groups: head trauma, post-upper respiratory infection, chronic sinonasal disease, toxic exposure, and idiopathic. All patients were examined using the Butanol Threshold Test (BTT) and Cross Cultural Smell Identification Test (CC-SIT). The patients’ subjective symptoms were recorded using the Visual Analog Scale (VAS). ResultsZZThe three tests showed significant correlations in different pairs (CC-SIT and BTT; r=0.512, p<0.001, BTT and VAS; r=0.558, p<0.001 and VAS & CC-SIT; r=0.567, p<0.001). Correlation results were lower in patients with olfactory disorders caused by an upper respiratory infection and head trauma than in those with olfactory disorders caused by sinonasal diseases.