Are You Engaged with Bodily Signals? Validation of the German Version of the Interoceptive Sensitivity and Attention Questionnaire (ISAQ) in Convenience Samples and Pathological Illness Anxiety

The conscious engagement with neutral and symptom-related bodily signals (i.e., interoceptive sensibility) is an important transdiagnostic factor whose assessment remains challenging. In two studies, we examined the psychometric properties and the validity of the German Interoceptive Sensitivity and Attention Questionnaire (ISAQ) assessing two convenience samples (N = 365 and N = 254), adults at risk for rosacea (N = 376) and 44 outpatients with pathological illness anxiety compared to 40 controls. Confirmatory factor analyses indicated the structure of the German ISAQ is best represented by the 3-factor model of the original version (F1: sensitivity to neutral bodily sensations, F2: attention to unpleasant bodily sensations, and F3: difficulty disengaging from unpleasant bodily sensations) with an acceptable model fit after consideration of modification indices. Reliability was acceptable for F1 and F2, but poor for F3. Higher correlations of F1 with measures of functional and of F2/F3 with measures of dysfunctional body focus indicated validity. Measurement invariance to the Dutch original was partially met. Persons with illness anxiety scored significantly higher in all ISAQ subscales. Comparable to the original, the German ISAQ is a valid instrument to assess neutral and negative body perception. The third subscale should be interpreted cautiously.