Extended version of the 'Sniffin’ Sticks' identification test: Test–retest reliability and validity

Background The extended, 32-item version of the Sniffin’ Sticks identification test was developed in order to create a precise tool enabling repeated, longitudinal testing of individual olfactory subfunctions. New method Odors of the previous test version had to be changed for technical reasons, and the odor identification test needed re-investigation in terms of reliability, validity, and normative values. Results In our study we investigated olfactory abilities of a group of 100 patients with olfactory dysfunction and 100 controls. We reconfirmed the high test–retest reliability of the extended version of the Sniffin’ Sticks identification test and high correlations between the new and the original part of this tool. In addition, we confirmed the validity of the test as it discriminated clearly between controls and patients with olfactory loss. Comparison with existing method(s) The additional set of 16 odor identification sticks can be either included in the current olfactory test, thus creating a more detailed diagnosis tool, or it can be used separately, enabling to follow olfactory function over time. Additionally, the normative values presented in our paper might provide useful guidelines for interpretation of the extended identification test results. Conclusions The revised version of the Sniffin’ Sticks 32-item odor identification test is a reliable and valid tool for the assessment of olfactory function.