The emetophobia questionnaire (EmetQ-13): psychometric validation of a measure of specific phobia of vomiting (emetophobia).

This study reports on the development and psychometric evaluation of a self-report assessment of the severity of symptoms of emetophobia. Using a sample of 95 individuals with emetophobia, and a matched sample of 90 control participants, a 13-items inventory was developed that showed a clear three-factor structure. The EmetQ-13 had good internal consistency (α=.82 in the clinical sample, and α=.85 in the control sample), and one-week test-retest reliability (rxx=.76). The EmetQ-13 showed significant correlations with another measure of emetophobia symptoms, the Specific Phobia of Vomiting Inventory, and related constructs such as disgust sensitivity. The measure showed excellent ability to classify emetophobic and non-emetophobic individuals, with correct assignment in 96.2% of cases. The EmetQ-13 also correlated significantly with a behavioural approach test using a vomit-like stimulus. The initial evaluation of the EmetQ-13 suggests that it is a reliable and valid measure for the assessment of emetophobia.