Development of a test to evaluate olfactory function in a pediatric population

Abstract

Objectives/hypothesis: This study evaluated two versions of a test for olfactory function to determine suitability for use in a pediatric population.

Study design: Cross-sectional cohort study.

Methods: In phase 1, 369 children (ages 3-17 years) and 277 adults (parents) were tested. Children began with identification and familiarity judgments to pictures representing target odors and distractors. Odors were administered via a six-item scratch and sniff test. Each answer sheet contained the correct odor source and three distractors. In phase 2, 50 children (ages 3-4 years) and 43 adults were given a revised version with eight odors judged more representative of the source and familiar to children.

Results: Both completion time and identification accuracy in phase 1 improved with age. Accuracy of children 5 years old and above equaled adults for two of the three best odors. In phase 2, adults' accuracy significantly improved relative to phase 1 (92% vs. 68%), and exceeded that of 4 year olds for four of eight odors and 3 year olds for seven of eight odors.

Conclusions: Children as young as 3 years of age can perform olfactory testing, but take longer than do older children and adults (7.44 vs. 5.66 vs. 3.71 minutes). Identification accuracy also increases as a function of age. The current six-item National Institutes of Health Toolbox Odor Identification Test is a brief, easily conducted test for evaluating olfactory ability. Collection of normative data for children of all ages and adults is needed to determine the clinical utility of the test and its interpretations for pathological conditions.

Fig. 1

Picture board used to evaluate familiarity and accuracy of the target and distractor pictures in phase 1. Children were asked if they could point to the appropriate picture when the experimenter named each of the 13 images (from left to right and top to bottom: banana, coffee, lemon, peanut butter, grapes, cinnamon, Play-Doh, bubble gum, chocolate, flower, mint, popcorn, and bread).

Fig. 2

Sample layout of four response choices for the target odor (cinnamon) and three distractors (bubble gum, grape, and mint). Children (and adults at Monell) were asked to point to the picture that best matched the odor they smelled. Adults at the Nemours site viewed the pictures and then circled the name of the item on a separate sheet.