Assessment of an abbreviated odorant identification task for children: a rapid screening device for schools and clinics

How well can young adults and children discriminate between odors?

It is widely believed that people can distinguish between many odors although there is limited empirical evidence. Odor discrimination tasks are employed much less often than other measures of olfaction, but, interestingly, performance is typically ~ 75% correct. This less-than-perfect performance is rarely highlighted, although it suggests that people may not be as good at discriminating odors as is commonly believed. Odor discrimination is understudied in children, and although available evidence suggests that it improves with age, children perform better when the task is simpler. In the present study, we explored odor discrimination in children and young adults with a relatively simple same-different task using common and uncommon odors. We found that children perform as well as young adults, but that overall performance was less than perfect and depended on the odors to be discriminated. We found evidence that ability to discriminate between odors improves as the difference in pleasantness of the odors increases. In a second experiment, we tested this directly by exploring whether odors that differ in pleasantness and edibility, two dimensions that appear to be important in olfactory perception, are easier to discriminate than odors that are the same on those dimensions. We found further evidence that odors that differ in pleasantness are easier to discriminate.

qU-Sniff - the development of a short version of the Universal "Sniffin' Sticks" test

OBJECTIVES

Extensive olfactory testing is sparsely applied in pediatric patients in clinical routine especially because of its time taking nature. Therefore a 5-item odor identification test (quick "U-Sniff", "qU-Sniff") from the 12-item "U-Sniff" test was developed.

METHODS

A total of 724 normosmic children between 6 and 17 years of age, divided in four age groups, were included in this retrospective study. Additionally, 17 children with congenital anosmia in the same age range were included. To calculate test-retest reliability 90 participants from the healthy group were tested twice.

RESULTS

The five most correctly identified odors from the 12-item "U-Sniff" test were: coffee (98 %), peach (95 %), flower (90 %), fish (88 %) and onion (84 %). Normosmic participants scored 4.71 ± 0.62 points on the "qU-Sniff" test. A significant correlation between results of the 12-item and 5-item test (n = 724; rs = 0.580; p < 0.001) and a significant test-retest reliability (rs = 0.626, p < 0.001) were shown. For "qU-Sniff" validation a ROC analysis to distinguish between anosmic patients and healthy controls was conducted for each age group separately. AUCs were as followed: i) 0.963 ± 0.018, p < 0,001; ii) 0.978 ± 0.013, p < 0.001; iii) 0.992 ± 0.006, p < 0.001; iv) 0.994 ± 0.005, p < 0.001. The cut-off value to determine anosmic and normosmic participants was <4 points.

CONCLUSION

With the "qU-Sniff" test, we present a short screening tool for clinical routine with <4 points as cut-off to initiate more detailed olfactory testing.

International consensus statement on allergy and rhinology: Olfaction

BACKGROUND

The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O).

METHODS

Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus.

RESULTS

The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies.

CONCLUSION

This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.

Assessment of Olfactory Function in Children and Adolescents: An Overview

Valid and reliable tools for assessing olfactory function are necessary for the diagnosis of olfactory dysfunction. Olfactory testing can be challenging in a pediatric population due to shorter attention span, linguistic development, and lower olfactory experience in this age group. The aim of this article is to present an overview about olfactory tests that are suitable for a pediatric population. Publications were included when reporting new developed methods of psychophysical olfactory testing in children or adaptation and applications of existing olfactory tests for a pediatric population. Olfactory tests for all 3 major aspects of olfactory function-olfactory threshold, odor discrimination, and odor identification-were included. Olfactory tests were evaluated regarding test validity, test reliability, normative data, and test availability. The current literature shows that several tests are available to assess olfactory function in children. Especially odor identification abilities in a pediatric population are well examined and understood. Tests for olfactory threshold and odor discrimination are less frequently used. In terms of the abovementioned evaluation criteria, only a few tests met all or 3 of these 4 criteria. Based on the current literature the following tests can be recommended for valid and reliable olfactory testing in children: "U-Sniff" odor identification test, the "Sniffin' Sticks" olfactory threshold test, pBOT-6 olfactory threshold and odor identification test, NIH-Toolbox, and Smell Wheel. Age has to be considered when evaluating olfactory function in children.

Effects of diversity in olfactory environment on children's sense of smell

Diversity in children's everyday olfactory environment may affect the development of their olfactory abilities and odor awareness. To test this, we collected data on olfactory abilities using the Sniffin' Sticks and odor awareness with Children's Olfactory Behaviors in Everyday Life Questionnaire in 153 preschool children and retested them one and a half year later. Parents completed an inventory on children's exposure to a variety of odors and on their own odor awareness using the Odor Awareness Scale. We controlled for the effects of age and verbal fluency on the children's performance. We found that the children's odor identification and discrimination scores differed as a function of parental odor awareness. Although these effects were rather small, they were commensurate in size with those of gender and age. To the best of our knowledge, this study is the first to present evidence that diversity in children's olfactory environment affects variation in their olfactory abilities and odor awareness. We suggest that future studies consider the long-term impact of perceptual learning out of the laboratory and its consequences for olfactory development.

Racial disparities in olfactory loss among older adults in the United States

BACKGROUND

Age-related olfactory loss (presbyosmia) substantially decreases quality of life, presages neurodegenerative disease, impairs nutrition, and predicts mortality. We sought to determine how race is associated with olfactory loss in older American adults in order to inform both health care and policy.

METHODS

The National Social Life, Health and Aging Project interviewed a cross-sectional nationally representative probability sample of older adults in the United States. African Americans and Hispanics were oversampled, providing power to detect disparities for these subgroups. As part of an omnibus survey of demographic, social, psychological, and biological measures, National Social Life, Health and Aging Project assessed the ability to verbally identify odors by presenting five odor pens. Multivariate ordinal logistic regression quantified racial differences in odor identification, and then tested potential confounders.

RESULTS

African Americans and Hispanics had markedly worse olfactory function (controlling for gender and age) compared with whites (p < .001), twice the magnitude of gender differences, and comparable to aging 9 years. Cognition, household assets, and education accounted for the disparity found among Hispanics but not among African Americans. Moreover, other potential confounders, such as physical or mental health, including tobacco and alcohol use, did not account for the African American health disparity, which remained significant (p = .001) after including these factors.

CONCLUSIONS

African Americans are more likely to suffer from presbyosmia, a health disparity not explained by gender, education, cognition, physical or mental health, and health behaviors. This novel health disparity may result from lifetime environmental exposures, diet, or genetic susceptibility. Dissecting the interactions among these putative mechanisms will provide insight into ameliorating this decline in critical human sensory function.

Identification of odors of edible and nonedible stimuli as affected by age and gender

This study investigated cued odor identification performance with a set of 64 natural common odors (half of edible and half of nonedible stimuli) in three groups of participants: one group of 30 young adults (mean age 25.3 years, range 18-30, SD 3.1) and two groups of older adults-20 young-old (mean age 64.4 years, range 60-69, SD 2.8) and 21 old-old (mean age 74.6 years, range 70-79, SD 2.5). The results showed that 49 of the 64 odors were correctly identified by over 70% of the participants in all groups. The odor identification performance of the young-old adults did not differ from that of the young adults. However, the oldest group showed a significant loss of performance in the task. Women in the young-old group performed better than men, whereas no gender differences were found in the other two age groups. The data obtained in this study will be useful for further perceptual and memory studies conducted in the olfactory modality with young as well as with older participants.

Human awareness and uses of odor cues in everyday life: Results from a questionnaire study in children

The Children's Olfactory Behavior in Everyday Life questionnaire was developed to assess attention to, and uses of, odors in real-life situations, and to evaluate individual variations. The tool comprises 16 items prompting self-reports of active seeking, awareness and affective reactivity to odors of food, people and the environment. Children (102 girls, 113 boys) aged 6–10 years participated in the study. The results revealed that girls were significantly more olfaction-oriented than boys, especially towards the odors of people, self and the environment. An increasing ability of children to describe the odor facets of their perceptual world was found between 6 and 10 years, partly due to ameliorating verbal skills. Finally, owning an “attachment object” was linked to olfactory reactivity to odors, especially in social and affective contexts. Overall, this research contributes to expand our understanding of the behavioral importance of odors in children and its individual variations, and it brings additional arguments against the prevalent concept of functional microsmaty applied to the human species.

Olfactory evaluation in children: application to the CHARGE syndrome

OBJECTIVE

To find an efficient tool for testing olfactory function in children and use it to investigate a group of children with CHARGE (coloboma, congenital heart disease, choanal atresia, mental and growth retardation, genital anomalies, and ear malformations and hearing loss) syndrome.

METHODS

We adapted for children an olfaction test that had just been validated in an adult French population and investigated a control group of 25 healthy children aged 6 to 13 years. We then tested the olfactory capacity of a group of 14 children with CHARGE syndrome, aged 6 to 18 years. A questionnaire was completed with the parents about their children's feeding difficulties and their ability to recognize odors in everyday life. We recorded and scored the histories of feeding behavior anomalies, the visual and auditory status, and current intellectual levels. MRI of the olfactory tracts and bulbs was analyzed for 9 of 14 children.

RESULTS

We showed that healthy children have similar olfactory function to that of the adult control group, which was representative of the general population, without any difference for either gender or age. We also showed that all children with CHARGE syndrome had olfactory deficiency. Half of them were anosmic, and the others had olfactory residual function (hyposmic). We found no association between olfactory deficiency and feeding behavior, visual or auditory impairment, or intellectual level. Parental subjective evaluations were accurate for only half of the group. All of the MRIs showed anomalies of the olfactory tracts and bulbs varying from moderate hypoplasia to complete aplasia, without any relation between the radiologic and the functional results.

CONCLUSIONS

Olfaction can be assessed in children, even the young and disabled. Our results support the proposition that rhinencephalon anomalies should be included as a major criterion for the diagnosis of CHARGE syndrome.

Assessment of the Sniff Magnitude Test as a clinical test of olfactory function

Olfactory threshold and odor identification tasks currently serve as the standard approaches to the clinical assessment of olfactory function. Although these methods can be used effectively with the average patient, they suffer from some limitations when used to evaluate children, people with cognitive impairment, or people from diverse cultural backgrounds. A novel approach to the clinical evaluation of olfactory function, the Sniff Magnitude Test, attempts to minimize the cognitive demands of an olfactory test and thereby overcome some of the limitations of alternative tests. This is achieved by measuring the reflex-like reduction in sniffing that occurs when a malodor is encountered. The reliability and the validity of the Sniff Magnitude Test were assessed by testing people on two occasions using the University of Pennsylvania Smell Identification Test (UPSIT), a butanol threshold task, the Alcohol Sniff Test, and the Sniff Magnitude Test. The test-retest reliability of the Sniff Magnitude Test was r=.80, higher than the butanol thresholds and Alcohol Sniff Test but somewhat lower than the UPSIT. Performance on the Sniff Magnitude Test (the sniff magnitude to a malodor relative to nonodorized air) was correlated between r=-.61 and r=-.66 with the other measures of olfactory function. This range of correlations was comparable to that observed between the butanol threshold, the UPSIT, and the Alcohol Sniff Test. Finally, evidence for the advantages of the Sniff Magnitude Test, as compared to the UPSIT, was provided by a study with young children. It is concluded that the Sniff Magnitude Test has significant potential as a clinical measure of olfactory function, and that further testing and development of this method are warranted.

Olfactory performance during childhood. II. Developing a discrimination task for children

OBJECTIVES

(1) To create a match-to-sample odorant discrimination task (MODT) for children and adolescents; (2) to assess whether nonolfactory factors affect olfactory performance more on an identification task than on the MODT; (3) to evaluate subjects with olfactory dysfunction; and (4) to create age-appropriate sets of odorants for use in the MODT format to test children of different ages.

STUDY DESIGN

We tested 75 normal children, aged 2 to 18 years, and 17 other subjects, aged 7 to 53 years, with known or suspected olfactory dysfunction, with the MODT. We compared the age trends in variability of scores on the MODT with those on an odorant identification task, using a weighted linear regression analysis.

RESULTS

The MODT was useful in children aged 5 years and older, but not generally in the 2- to 4-year-old children. There was an appreciable age trend in the variability of the scores on the identification task but not on the MODT. Mean MODT scores for subjects with suspected or known olfactory dysfunction were far below average. Finally, we created four sets of odorants that will likely be sensitive to age-specific changes in olfactory performance.

CONCLUSIONS

The MODT appears to be a suitable test instrument to assess olfaction in children aged 5 and older and is less likely to be influenced by nonolfactory factors than an identification task. According to our preliminary results, it is likely that the MODT will allow us to detect olfactory deficits in children of many ages.