Reliability and validity of the Chinese version of the questionnaire of olfactory disorders (QOD) when used with patients having olfactory dysfunction

Validation of the questionnaire of olfactory disorders (QOD) for the Brazilian population

BACKGROUND

The incidence of olfactory disorders has increased in recent years, mainly related to COVID-19 infection. In Brazil, over 37 million cases of COVID-19 have been reported, and approximately 10 % of those cases continue to experience olfactory disorders for more than one month. Despite the significant negative impact on well-being, there is currently no validated instrument to assess how olfactory disorders impact the quality of life in Brazil.

OBJECTIVES

This study aimed to validate the Questionnaire of Olfactory Disorders (QOD) for Brazilian Portuguese.

METHODS

The authors first performed translation, back-translation, expert review, pre-testing, psychometric evaluation and cultural adaptation of the English version of the questionnaire. To assure linguistic and conceptual equivalence of the translated questionnaire, 126 participants from two Brazilian states and varying degrees of olfactory loss answered the QOD and the World Health Organization Quality of Life bref (WHOQOL-bref) questionnaires. The University of Pennsylvania Smell Identification Test (UPSIT®) was used to quantify the olfactory loss. Furthermore, to evaluate the reliability of the Portuguese version a test-retest was performed on a subgroup of patients. The authors observed a high Cronbach's alpha (α = 0.86) for internal consistency of the quality of Life (QOD-QOL) statements.

FINDINGS

As expected, there was a negative correlation between QOD-QOL and UPSIT® (Spearman's ρ = -0.275, p = 0.002), since QOL score increases and UPSIT® score decreases with worsening of olfactory function. Correlations were moderate between QOD-QOL and WHOQOL-bref mean (Spearman's ρ = -0.374, p < 0.001) and weak to moderate between the QOD-QOL and Visual Analog Scale of the QOD regarding professional life, leisure, and private life (Spearman's ρ = -0.316, p = 0.000; Spearman's ρ = -0.293, p = 0.001; Spearman's ρ = -0.261, p = 0.004; respectively).

CONCLUSION

In conclusion, the authors have demonstrated a high internal consistency and validity of the Brazilian Portuguese version of the QOD for evaluating the quality of life in individuals with olfactory disorders.

Patterns of Olfactory Impairment Among Patients with Uncontrolled Chronic Rhinosinusitis

OBJECTIVES

Self-reported olfactory dysfunction is an assessment component criterion for chronic rhinosinusitis (CRS) disease control of the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS). No studies have objectively explored olfactory function across different psychophysical olfactory domains among patients with uncontrolled CRS. We aimed to investigate the patterns of olfactory impairment in patients with uncontrolled CRS with Sniffin' Sticks test.

METHODS

A total of 79 patients with CRS were prospectively recruited and assessed for disease control based on the EPOS criteria. Sniffin' Sticks test scores, olfactory cleft computed tomography (CT) scores, olfactory cleft endoscopy scale (OCES), questionnaire of olfactory disorders-negative statements (QOD-NS), and sinonasal outcome test-22 (SNOT-22) were obtained. Multiple logistic regression was applied to explore risk factors of uncontrolled CRS.

RESULTS

Twenty-six percent of patients with CRS presented with uncontrolled status. The odor threshold (OT) (p = 0.005), odor identification (OI) (p = 0.041), and thresholds-discrimination-identification (TDI) (p = 0.029) scores were significantly lower in patients with uncontrolled CRS when compared with patients with controlled CRS. Furthermore, patients with uncontrolled CRS presented with a significantly increased percentage of anosmia (p = 0.014), olfactory cleft CT score (p = 0.038), OCES (p = 0.016), QOD-NS(p = 0.008), and SNOT-22 (p < 0.001) scores than patients with controlled CRS. After adjusting for patient demographics, as for the subdomain of olfaction, only the OT score was an independent risk factor for uncontrolled CRS (odds ratio = 0.604; p = 0.030). The OT scores less than 5.950 were the best predictor of uncontrolled CRS.

CONCLUSION

Patients with uncontrolled CRS demonstrated distinct patterns of olfactory impairment, and a reduced olfactory threshold was highly associated with uncontrolled CRS.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:2341-2348, 2024.

Validity and Reliability of the Malay Questionnaire for Olfactory Disorders

Background

Olfactory disorders (OD) are an umbrella term for a diverse group of smell problems. Numerous tests and questionnaires have been formulated to identify and test the severity of smell impairment, which is not readily available or translated for the Malaysian population. This study aimed to translate the Questionnaire for Olfactory Disorders (QOD) and validate and test the reliability of the Malay Questionnaire for Olfactory Disorders (mQOD).

Methods

This cross-sectional study was conducted in two tertiary centres. A forward and backward translation was conducted for the QOD. The translated questionnaire was distributed to subjects with self-reported smell disorders on days 1 and 7. Internal consistency was analysed using Cronbach's alpha and test-retest reliability was tested with an intraclass correlation coefficient. Confirmatory factor analysis was performed to test construct validity.

Results

A total of 375 participants were recruited, 52 dropped out and 323 completed the questionnaire a second time. The Cronbach's alpha coefficient was 0.537 for parosmia (P), 0.892 for life quality (LQ), 0.637 for sincerity (S) and 0.865 for visual analogue score (VAS). The intraclass correlation coefficient (ICC) for domain scores was > 0.9, while the ICC for all items was good to excellent. A three-factor model for mQOD showed an acceptable fit with indices chi-square value (CMIN)/degree of freedom (DF) = 3.332, Tucker-Lewis fit index (TLI) = 0.923, comparative fit index (CFI) = 0.939, root mean square error of approximation (RMSEA) = 0.079 and standardised root mean square residual (SRMR) = 0.0574.

Conclusion

The mQOD is a valid and reliable tool for assessing OD in patients.

[Detection of disorders of the chemical senses-assessment of state of health by those affected]

Although hundreds of thousands of people seek medical help every year because of smell and taste disorders, the burden on patients is often underestimated by health care professionals. Numerous studies have demonstrated the impact of disorders of the chemical senses on quality of life. In clinical practice, the Questionnaire of Olfactory Disorders (QOD) has proven to be a good measure of the impact of olfactory loss on everyday life. Patient-reported outcome measures (PROMs) should therefore be used more frequently for better recording and assessing the needs of patients. In addition to education and treatment by specialized clinics, the provision and optimization of information platforms, support groups, and organizations should be promoted in Germany.

Reliability and validity of the Polish version of the Questionnaire of Olfactory Disorders

Background

The comprehensive counseling of patients with olfactory dysfunctions requires accurate diagnosis. The recommendations include subjective assessment. The Questionnaire of Olfactory Disorders (QOD) is a disease-specific questionnaire for the subjective evaluation of olfactory dysfunctions.

Material

The study included 54 patients with olfactory dysfunctions, who were recruited to the study group (SG). The other 47 patients without the history of olfactory dysfunction and nasal cavity pathology were voluntarily allocated to the control group (CG). The protocol of the study was introduced to each patient and included: olfactory testing with Sniffin' Stick test, fulfillment of the Polish version of World Health Organization Quality of Life brief questionnaire and completing of the Polish version of the QOD. All participants (101) were invited for refilling the QOD questionnaire after 2 weeks for the test-retest statistics.

Results

The Polish QOD statements were significantly correlated and met the requirement by having test-retest correlation larger than 0.7. We found that internal consistency of the test measured by Cronbach's alpha coefficient was very high. The mean scores of the QOD test in normosmic SG patients were compared with corresponding scores in normosmic CG patients using U Mann-Whitney test. The analysis revealed statistically significant differences on mean QOD scores for each domains except QOD-S between both groups.

Conclusions

The Polish version of the QOD demonstrated high rate of the validity and the reliability. This instrument may be widely used in research projects and clinical practice concerning olfactory disorders in Polish patients.

Level of Evidence

NA.

Italian version of the brief Questionnaire of Olfactory Disorders (brief-IT-QOD)

Objective

To evaluate the reliability and validity of the Italian brief-QOD (Brief-IT-QOD).

Methods

The study consisted of six phases: item generation, reliability analysis (112 dysosmic patients for internal consistency analysis and 61 for test-retest reliability analysis), normative data generation (303 normosmic subjects), validity analysis (comparison of Brief-IT-QOD scores of healthy and dysosmic subjects and scores correlation with psychophysical olfactory testing (TDI) and SNOT-22 scores), responsiveness analysis (10 dysosmic chronic rhinosinusitis with nasal polyps (CRSwNP) patients before and after biologic therapy), and cut-off value determination (ROC curve analysis of Brief-IT-QOD sensitivity and specificity).

Results

All subjects completed the Brief-IT-QOD. Internal consistency (α > 0.70) and test-retest reliability (ICC > 0.7) were acceptable and satisfactory for both questionnaire subscales. A significant difference between dysosmic and control subjects was found in both subscales (p < 0.05). Significant correlations between subscales scores and TDI and SNOT-22 scores were observed. Brief-IT-QOD scores before treatment were significantly higher than after biological therapy.

Conclusions

Brief-IT-QOD is reliable, valid, responsive to changes in QoL, and recommended for clinical practice and outcome research.

Olfactory Disorders Questionnaire: Scaling severity of quality-of-life impact

BACKGROUND

The Olfactory Disorders Questionnaire (ODQ) is widely used for patients suffering from olfactory disorders to depict the impact on quality of life. The aim of this study was to scale and produce reference values for patients ODQ score according to Becks Depression Inventory (BDI) severity.

METHODS

In this prospective study, a cross-sectional anonymous survey was created, which combined EQ-5D-5L, BDI and ODQ. Correlation was calculated between the three questionnaires. Receiver operator characteristic curves were created to produce cut-off values for ODQ scores based on three BDI categories (mild, borderline clinical and moderate-to-severe depression).

RESULTS

Of the 578 who responded to the survey, 445 completed all sections and were included in the study. Majority were female (n = 327,73.5%), median age group 55-70 years (n = 193,43.4%). There was a strong correlation between BDI score and total ODQ score. There was a clear gradient in total ODQ score for each BDI classification; those with mild depression had the lowest mean ODQ score (101.8, range 39-168), those with moderate-to-severe depression had the highest (138.24, range 74-177). Due to overlapping of confidence intervals we were unable to grade the ODQ score.

CONCLUSION

The study was unable to generate reference values for the ODQ due to lower numbers of patients with borderline clinical to extreme depression. However, we were able to appreciate the general trend, that the higher the ODQ score, the higher the risk of depression. These findings should guide clinical practice to ensure appropriate care and support is provided for those with olfactory dysfunction.

The Correlation between the Results of the Sniffin' Sticks Test, Demographic Data, and Questionnaire of Olfactory Disorders in a Hungarian Population after a SARS-CoV-2 Infection

BACKGROUND

After a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, smell disorders frequently occur, significantly affecting patients' quality of life (QoL).

METHODS

110 patients with persistent olfactory disorder after coronavirus infection were enrolled. These patients underwent chemosensory testing using the Sniffin' Sticks test, and completed the Questionnaire of Olfactory Disorders (QOD).

RESULTS

30% of the patients reported anosmia, and 70% reported hyposmia. Upon comparing subjective and chemosensory testing categories, good category matching was observed in 75.3% (i.e., anosmia based on both methods in 10 and hyposmia in 48 cases). Statistical analysis using the Chi-square test revealed a significant result (p = 0.001 *). Between the TDI (i.e., Threshold, Discrimination, Identification) results of the three subjective report groups (i.e., hyposmia, anosmia, and parosmia), no significant differences were observed. When the TDI and QOD results were compared, no consistent significant correlations were found in most TDI and QOD outcomes. Between the TDI and Scale 2 results, a significant, although slight correlation was observed by the Spearman's (rho = 0.213, p = 0.027 *) and Pearson's (rho = 0.201, p = 0.037 *) tests.

CONCLUSIONS

The nonsignificant correlation between objective and subjective methods suggests that these results should be interpreted independently. Moreover, adequate management is essential even in mild cases.

Adaptation and Validation of Portuguese Version of Olfactory Disorders Questionnaire (PT-ODQ)

Introduction

Olfactory dysfunction (OD) is often a devaluated sensorial affection. The objective evaluation of this dysfunction doesn’t evaluate its compromise in patients’ daily life. Therefore, the use of a Portuguese-validated tool is of uttermost importance to objectively scale the pathology presented by these patients.

Objective

We aim to validate and cross-culturally adapt the Olfactory Disorders Questionnaire (ODQ) in the Portuguese language.

Methods

A prospective study was carried out to evaluate and compare 56 consecutive patients who had olfactory disorders and 54 asymptomatic controls. A cross-cultural adaptation process was taken into account in order to transform the original English tool into a valid Portuguese version. We explored the psychometric properties of the European-Portuguese version of the Portuguese version of ODQ (PT-ODQ) concerning its internal consistency, reproducibility, feasibility, and discriminatory validity.

Results

Cronbach alpha for the tool was 0.924 showing strong internal consistency. We also found a statistically significant difference in PT-ODQ between patients with olfactory disorders and patients without olfactory disorders, according to the Mann-Whitney test.

Conclusions

The PT-ODQ seems to be a valid tool for assessing the individual effect of olfactory disorders on patients’ quality of life and, therefore, could be applied in olfactory disorders research and daily practice.

Predictive significance of the questionnaire of olfactory disorders-negative statements for olfactory loss in patients with chronic rhinosinusitis

Objectives

The questionnaire of olfactory disorder-negative statements (QOD-NS) is a valid and reliable instrument for assessing the olfactory-specific quality of life. This study aimed to explore the association between the QOD-NS and objective olfactory metrics (including objective olfactory cleft assessment) and then evaluate the predictive significance of the QOD-NS for olfactory loss in Chinese patients with chronic rhinosinusitis (CRS).

Methods

A total of 70 patients with CRS were enrolled in the study. Olfaction was assessed with Sniffin’ Sticks. The olfactory cleft was assessed by the sinus CT scan and nasal endoscopy (the Lund–Mackay olfactory cleft scale, LM-OC and olfactory cleft endoscopy scale, OCES). The QOD-NS and its short version were utilized to assess the patient-reported olfaction. The predictors associated with olfactory loss were analyzed by the logistic regression analysis. The optimal cutoff points of the predictors were determined by the receiver-operating characteristic curves and the Youden index.

Results

The TDI score in patients with CRS significantly correlated with the QOD-NS (r = − 0.755, P < 0.001), OCES (r = − 0.520, P < 0.001), LM-OC (r = − 0.615, P < 0.001). After adjusting for patient demographics and comorbidities, QOD-NS was significantly associated with olfactory dysfunction [odds ratio (OR) = 1.243; P = 0.001] and anosmia in patients with CRS (OR = 1.838; P = 0.006). Furthermore, the QOD-NS significantly correlated with the LM-OC (r = 0.610, P < 0.001), and the OCES (r = 0.464, P < 0.001) in patients with CRS. The QOD-NS had the highest predictive value for olfactory dysfunction (optimal cutoff = 10.5; Youden index = 0.635; area under the curve = 0.861) and anosmia (optimal cutoff = 20.5; Youden index = 0.790; area under the curve = 0.928) in patients with CRS.

Conclusion

The QOD-NS showed high validity and correlated well with objective olfactory metrics and olfactory cleft assessment in patients with CRS. The QOD-NS was a reliable predictor for olfactory dysfunction and anosmia in patients with CRS, which may aid in the fast screening of olfactory loss in the clinic.

Reliability and validity of a brief version of the Questionnaire of Olfactory Disorders (brief QOD) in patients with olfactory dysfunction

BACKGROUND

The aim of this study was to determine the reliability and validity of the brief version of Questionnaire of Olfactory Disorders (brief QOD).

METHODS

A total of 372 patients participated in this study. Olfactory function was examined using the Sniffin' Sticks test. The brief version of QOD, including 4 items concerning parosmia (QOD-P), 7 items concerning quality of life (QOD-QOL), and 3 visual analog scales to rate disease burden, awareness of the disorder and issues related to professional life (QOD-VAS), was used to assess subjective information on olfactory dysfunction. We evaluated the split-half reliability, internal consistency and validity of the brief QOD.

RESULTS

The split-half reliability was 0.60 (QOD-P), 0.87 (QOD-QOL), and 0.66 (QOD-VAS), respectively. The Cronbach's α coefficient was 0.63 (QOD-P), 0.87 (QOD-QOL), and 0.71 (QOD-VAS), respectively. Olfactory function was found to be associated with QOD-P, QOD-QOL and QOD-VAS.

CONCLUSIONS

The brief QOD is a suitable scale for the assessment of subjective severity of olfactory dysfunction for purposes such as treatment counseling, disability assessment, treatment control, and research in patients with olfactory disorder.

Development of a Self-reported Olfactory Dysfunction Questionnaire (SODQ) to screen olfactory disorders in China

BACKGROUND

The diagnosis of olfactory dysfunction is challenging given the negligence during routine physical examination, inconvenience of diagnosis in clinical practice, and the inattention to cross-cultural adaptability. The study aimed to develop and validate a simple and effective self-reported olfactory dysfunction questionnaire (SODQ) for the initial screening of clinical olfactory disorders in China.

METHODS

A total of 121 subjects participated in the study; of these, 96 subjects completed the T&T olfactometer test and 12-item questionnaire, and 25 participants were retested using the SODQ after one week. The T&T olfactometer test examined the olfactory function and the questionnaire measured the ability to perceive common odors in daily life. We evaluated the factor structure, reliability, validity, and discriminative ability of the SODQ.

RESULTS

The final version of the SODQ consisted of 10 items with one factor. Test-retest and internal consistency were excellent. Convergent validity of the questionnaire with the T&T olfactory test was high. Furthermore, the discrimination ability was high for the questionnaire with an area under the curve of 0.95 and a cut-off point of 22.

CONCLUSIONS

The SODQ is a brief, valid, and repeatable tool that has the potential to effectively screen for clinical olfactory disorders from a subjective perspective.

Validation of the olfactory disorders questionnaire for English-speaking patients with olfactory disorders

OBJECTIVES

To adapt the existing German language olfactory disorders questionnaire for use with English-speaking patients. To validate the adapted version for routine clinical use.

DESIGN

The translated version of the original German questionnaire was revised with a patient and a clinician to reflect British language and culture. Patients attending an olfactory dysfunction clinic were recruited to perform the adapted questionnaire on two occasions at least 1 month apart. Additional online participants completed the questionnaire via the charity Fifth Sense.

MAIN OUTCOME MEASURES

Retest reliability of the English olfactory disorders questionnaire (eODQ) in affected patients including potential for redundancy in any of the included questions. Correlation of eODQ scores with Sniffin' Sticks scores.

RESULTS

Eighty-seven patients reporting olfactory dysfunction were recruited and had a mean age of 48 with 35% of them being male; 50 datasets were available for analysis. A total of 957 members of the charity entered responses into the online questionnaire; 699 responses could be scored with participants' mean age of 55 years and with 69% reporting as female. The eODQ score and Sniffin' Sticks threshold, discrimination and identification score at timepoint 1 were correlated to assess for concurrent validity, (r = -0.15, P = 0.17) and showed no significant correlation. Female participants had a significantly higher mean total eODQ score than men, 55.75 compared to 52.28 (P = 0.001). The average score was 54.7 (SD 13.5) with a range from 26 to 87. The internal consistency of the questionnaire was good with a Cronbach's alpha of 0.90 (confidence intervals 0.89, 0.91).

CONCLUSIONS

The results of this study support the use of the eODQ in a native English-speaking population and highlight the different distinctions between "objective" testing of olfaction with the Sniffin' Sticks test, and the patient reported impact of olfactory dysfunction on daily life. These two types of assessment can be easily administered in an outpatient setting and used in the assessment and management of olfactory dysfunction.

MR Imaging-Based Evaluations of Olfactory Bulb Atrophy in Patients with Olfactory Dysfunction

BACKGROUND AND PURPOSE

Although the olfactory bulb volume as assessed with MR imaging is known to reflect olfactory function, it is not always measured during olfactory pathway assessments in clinical settings. We aimed to evaluate the utility of visual olfactory bulb atrophy and neuropathy analyses using MR imaging in patients with olfactory dysfunction.

MATERIALS AND METHODS

Thirty-four patients who presented with subjective olfactory loss between March 2016 and February 2017 were included. Patients underwent a nasal endoscopic examination, olfactory testing with the Korean Version of the Sniffin' Sticks test, and MR imaging. All patients completed the Sino-Nasal Outcome Test and Questionnaire of Olfactory Disorders. Olfactory bulb atrophy and neuropathy were evaluated on MR images by 2 head and neck radiologists.

RESULTS

The etiology of olfactory loss was chronic rhinosinusitis with/without nasal polyps in 15 (44.1%) patients, respiratory viral infection in 7 (20.6%), trauma in 2 (5.9%), and idiopathic in 10 (29.4%) patients. Although 10 (29.4%) of the 34 patients were normosmic according to the Sniffin' Sticks test, their scores on the other tests were like those of patients who were hyposmic/anosmic according to the Sniffin' Sticks test. However, the detection rate of olfactory bulb atrophy was significantly higher in patients with hyposmia/anosmia than it was in patients with normosmia (P = .002). No difference in olfactory bulb neuropathy was identified among patients with normosmia and hyposmia/anosmia (P = .395).

CONCLUSIONS

MR imaging evaluations of olfactory bulb atrophy can be used to objectively diagnose olfactory dysfunction in patients with subjective olfactory loss.