Capturing qualitative olfactory dysfunction with PARPHAIT: the parosmia, phantosmia, and anosmia test

BACKGROUND: The assessment of qualitative olfactory symptoms is characterised by heterogeneous and unstandardised tools. To improve the means of capturing symptoms and subsequent treatment and care, this study aimed to develop a novel questionnaire, the parosmia, phantosmia, and anosmia test (PARPHAIT). METHODS: PARPHAIT was distributed to 165 participants with qualitative olfactory symptoms mainly due to COVID-19. The content was evaluated in participants with olfactory dysfunction, and an exploratory factor analysis (EFA) and internal consistency assessment was performed to assess underlying constructs and their reliability. RESULTS: PARPHAIT was scored as suitable, although suggestions for improvement were made. The EFA suggested a four-factor model with 34 items, all having factor loadings over 0.63. The factors had good to excellent reliability. CONCLUSIONS: This study aimed to develop a novel questionnaire, PARPHAIT, and evaluate its content and factor structure. The content and format were satisfactory, but had potential for improvement. EFA resulted in a four-factor, 34-item model with good to excellent internal consistency. PARPHAIT is only just developed and will need to be validated in different populations and confirmed with respect to its factor structure. However, PARPHAIT bears potential of being a robust, comprehensive - yet symptom-specific -, and standardised tool of capturing olfactory dysfunction.