The trigeminal function questionnaire (TriFunQ): a tool for clinical and research use

The purpose of the study was to develop a self-reporting measure of trigeminal function, addressing the need for the participants' self-perception of comfort and sensitivity related to trigeminal sensations. A 15-item questionnaire was designed and tested on the sample of n = 1,001 participants from the general population in Dresden, Germany, aged from 18 to 86. For validation included were ratings of nasal trigeminal stimuli using ammonium, lateralization of eucalyptol as a measure of trigeminal sensitivity, odor identification, and self-ratings of nasal airflow and olfactory function. Based on factor analyses, the initially intended structure of the questionnaire was revised to improve the tool's overall psychometric quality. Originally intended structure was not well supported. Exploratory factor analysis based on a scree plot indicated 1-factor solution, with the final version comprising 8 carefully selected items, providing the best fit. The questionnaire presented good reliability (Cronbach's α = 0.74) and satisfying validity, based on correlations with other self-reporting measures and group comparisons. Invariance analysis across gender suggested the use of separate norms for men and women. The trigeminal function questionnaire is a brief, reliable and valid measure for assessing self-perception of trigeminal function.