Development of a Brief Self-Report Inventory to Measure Olfactory Dysfunction and Quality of Life in Patients with Problems with the Sense of Smell

Large population-based studies using validated olfactory tests have shown that about 20 % of individuals aged 20 to 90 years have impaired olfactory function. The goal of the present study was the development of an easy to administer and reliable questionnaire to assess self-reported olfactory functioning in patients suffering from problems with the sense of smell. A cross-sectional, psychometric study using factor analysis and internal consistency methodology was performed to develop the 12-item questionnaire for the assessment of self-reported olfactory functioning and olfaction-related quality of life (ASOF). Discriminative validity of the three ASOF scales was assessed by comparing healthy controls and patients with problems with the sense of smell. Three hundred and thirteen normal controls with intact olfaction and 35 patients with olfactory dysfunction were included. All subjects included in the study were evaluated for olfactory dysfunction by means of the Sniffin’ Sticks. The ASOF can be subdivided into three domains: the one-item subjective olfactory capability scale (SOC), the five-item self-reported capability of perceiving specific odors scale (SRP), and the six-item olfactory-related quality of life (ORQ) scale. All three scales discriminated significantly between healthy controls and patients. The ASOF measures subjective olfactory functioning reliably and consistently, in normosmic subjects as well as in patients with olfactory dysfunction. The ASOF is a clinically relevant and practical diagnostic tool with very good psychometric properties. This new questionnaire may be helpful in the comprehensive evaluation of patients with olfactory disorders.