The 40-item Monell Extended Sniffin' Sticks Identification Test (MONEX-40)

Background: Most existing olfactory identification (ID) tests have the primary aim of diagnosing clinical olfactory dysfunction, thereby rendering them sub-optimal for experimental settings where the aim is to detect differences in healthy subjects' odor ID abilities. Materials and methods: We have developed an extended version of the olfactory ID subtest of the Sniffin' Sticks test battery to better assess the variability in ID scores and thereby olfactory abilities of healthy, adult individuals. Twenty-four odorants, corresponding cue labels, and distractor labels were added to the existing 16-item Sniffin' Sticks ID test to create the 40-item Monell Extended Sniffin' Sticks Identification Test (MONEX-40). The MONEX-40 was administered to 259 healthy young subjects, of which 72 were retested on an average of 212 days (SD 112 days) later. Results: The added odor items demonstrated good validity, as shown by a significant correlation of the results with the original 16-item ID test. In addition, the MONEX-40 achieved a significant test-retest and split-half reliability. Conclusions: Taken together, these results suggest that the MONEX-40 is a reliable method for experimental assessment of odor ID ability in healthy, young individuals. Moreover, its use of a wider range of odors allows the experimenter to present subsets of the MONEX-40 within the same experiment while maintaining statistical power. (C) 2011 Elsevier B.V. All rights reserved.