Testing the Use of “Clinical Checks” With the International Trauma Questionnaire to Measure PTSD and Complex PTSD

Shevlin, Mark; Hyland, Philip; Brewin, Chris R.; Cloitre, Marylene; Karatzias, Thanos; Redican, Enya

Abstract

Background: The International Trauma Questionnaire (ITQ) is the most widely used measure of ICD-11 Posttraumatic Stress Disorder (PTSD) and Complex PTSD (CPTSD). This self-report scale has been used to estimate prevalence rates of these disorders in general population and clinical samples but concerns abound that prevalence estimates derived from self-report measures are too high. To address this concern, we previously introduced the concept of adding ‘clinical checks’ to self-report measures to ensure initial responses reflected the intended clinical meaning of the scale item. Here we provide a rationale for adding clinical checks to the ITQ, describe the process of developing them, and demonstrate their effect at the symptom, cluster, and disorder levels in a general population sample.

Methods: A team of researchers and clinicians, including those who developed the ITQ, developed clinical checks for all ITQ items. These were tested using data from a non-probability quota-based representative sample of adults from the United Kingdom (N = 975).

Results: Use of clinical checks led to decreases in symptom endorsements ranging from 18.0% to 43.9%, and symptom cluster requirements from 19.1% to 35.9%. Disorder prevalence estimates without the clinical checks were 5.4% for PTSD and 9.5% for CPTSD. With the clinical checks, prevalence estimates dropped to 3.8% for PTSD (relative decrease = 29.6%) and 4.9% for CPTSD (relative decrease = 48.4%).

Conclusion: Clinical checks can be easily embedded into the ITQ and have a significant effect on prevalence estimates. We contextualise these results in relation to existing literature on population prevalence estimates derived from clinical interviews, and discrepancies between clinical interviews and self-report measures.

Citation

Shevlin, M., Hyland, P., Brewin, C. R., Cloitre, M., Karatzias, T., & Redican, E. (2025). Testing the Use of “Clinical Checks” With the International Trauma Questionnaire to Measure PTSD and Complex PTSD. Acta Psychiatrica Scandinavica, 152(1), 49-59. https://doi.org/10.1111/acps.13799

• Journal Article Type: Article
• Acceptance Date: Mar 1, 2025
• Online Publication Date: Mar 23, 2025
• Publication Date: 2025-07
• Deposit Date: Mar 3, 2025
• Publicly Available Date: Mar 3, 2025
• Journal: Acta Psychiatrica Scandinavica
• Print ISSN: 0001-690X
• Electronic ISSN: 1600-0447
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 152
• Issue: 1
• Pages: 49-59
• DOI: https://doi.org/10.1111/acps.13799
• Keywords: CPTSD, diagnosis, ICD-11, PTSD
• Public URL: http://researchrepository.napier.ac.uk/Output/4163699