The Development and Validation of a Self-Report Instrument that assesses ICD-11 Posttraumatic Stress Disorder (PTSD) and Complex PTSD: The Complex Trauma Inventory (CTI)
Justin M. Litvin, M.A., Patricia Kaminski Ph.D. and Shelley A. Riggs, Ph.D.
November 22, 2017
The work group editing trauma disorders for the eleventh edition of the International Classification of Diseases (ICD-11) made several changes (Maercker et al., 2013). Specifically, they simplified the criteria for posttraumatic stress disorder (PTSD) in an effort to decrease comorbidity with other disorders (e.g., mood and anxiety disorders) and added a new trauma disorder called “Complex PTSD” (CPTSD).This change in the ICD-11 criteria will not only affect the assessment, treatment, and billing procedures of trauma disorders in countries that use the ICD-11 as their primary mental health taxonomy, but it may also change these procedures in the United States. According to the Health Insurance Portability and Accountability Act (HIPAA), mental health providers are required to use the current ICD diagnostic and medical codes in order to receive compensation for professional services. If a revised HIPAA law extends this practice to the ICD-11, American mental health providers will need to switch to the ICD-11 trauma disorder definitions.
Since there is a significant shift in the definition of PTSD and a new trauma disorder is proposed, new assessment tools are needed to measure these novel constructs. We developed and validated a new measure of PTSD and CPTSD (The Complex Trauma Inventory; CTI) according to the proposed ICD-11 trauma disorder elements.
For this study, we carefully examined the proposed ICD-11 trauma disorder elements and symptoms and developed two to four items to assess each symptom to generate the initial item pool. This list of items was independently reviewed by three trauma experts and was edited accordingly. We then recruited two separate samples of diverse college students (n1 = 391; n2 = 391) who reported exposure to at least one traumatic event and at least occasional functional impairment. We used exploratory factor analyses on the responses from one sample to reduce the original 50 items to the 20 items that constitute the CTI. We then used a series of confirmatory factor analyses (CFAs) to assess seven different possible trauma disorder models based on the work of Karatzias and colleagues (2016).
The CFAs supported the ICD-11 trauma model above and beyond the alternative models. These results are consistent with the findings from Karatzias and colleagues (2016), despite substantial differences in various sample characteristics (e.g., type of trauma experienced, symptom severity, age, geographic location), suggesting the proposed ICD-11 trauma taxonomy is relatively stable across populations.
The results from our study identified five advantageous CTI characteristics: (a) the CTI is the first published self-report instrument that is consistent with the ICD-11 trauma disorders. (b) It was designed to assess both the intensity and frequency of the trauma-related symptoms which helps the mental health professional gain a better understanding of the respondent’s clinical presentation. This design, versus the traditional self-report scales that only assess how bothered the respondent is by a symptom, may better aid the tracking of symptom change which can inform treatment progress. (c) The CTI was designed to have at least three items per first-order factor in order to allow researchers to explore how different trauma elements are related to each other and other mental health constructs using higher-level statistical analyses (e.g., SEM). (d) The instrument has excellent psychometric properties (i.e., content validity, structural validity, convergent validity, discriminant validity). (e) It is gender invariant and can be used with both male and female populations. Our study therefore developed a brief, ICD-11-consistent and psychometrically-sound instrument that is tailored to assist the needs of both mental health professionals and researchers. The CTI is available for free on our website: http://psychology.unt.edu/cti. Please contact [email protected] if you have any questions or comments.
References
Maercker, A., Brewin, C. R., Bryant, R. A., Cloitre, M., Reed, G. M., van Ommeren, M., & ... Saxena, S. (2013). Proposals for mental disorders specifically associated with stress in the International Classification of Diseases-11. The Lancet, 381(9878), 1683-1685. doi:10.1016/S0140-6736(12)62191-6
Karatzias, T., Shevlin, M., Fyvie, C., Hyland, P., Efthimiadou, E., Wilson, D., Roberts, N., Bisson, J., Brewin, C. R., & Cloitre, M. (2016). An initial psychometric assessment of an ICD-11 based measure of PTSD and Complex PTSD (ICD-TQ): Evidence of construct validity. Journal of Anxiety Disorders, 44, 73-79. http://dx.doi.org/10.1016/j.janxdis.2016.10.009
Discussion Questions:
- What do you look for when considering what assessment tools to use? How do the CTI characteristics identified in this study “measure up” to these standards?
- What are the advantages and disadvantages of assessing the intensity and frequency of a symptom separately versus just asking how bothered someone is by a symptom?
- How can we improve the measurement of trauma disorders? What is the future of psychological measurement?
Reference Article
Litvin, J. M., Kaminski, P. L. and Riggs, S. A. (2017), The Complex Trauma Inventory: A Self-Report Measure of Posttraumatic Stress Disorder and Complex Posttraumatic Stress Disorder. JOURNAL OF TRAUMATIC STRESS. doi:10.1002/jts.22231
Author Biographies:
Justin M. Litvin is a fifth year in the counseling psychology doctoral program at the University of North Texas. His research interests include the psychological effects of trauma, measurement of trauma disorders, and coping strategies.
Dr. Patricia "Trish" L. Kaminski earned her doctorate in psychology (counseling) at Colorado State University. Her interest in the construct of Complex Post-traumatic Stress Disorder began as a postdoctoral fellow in clinical psychology at the Menninger Clinic (1995-1997). Dr. Kaminski, an Associate Professor of Psychology at the University of North Texas, has published and presented more than a dozen papers related to interpersonal trauma.
Shelley A. Riggs, Ph.D., is a licensed psychologist and Fellow of APA Division 43. She is currently a Professor and Director of the Family Attachment Lab at the University of North Texas. Dr. Riggs and her research team investigate the roles of family interactions, attachment relationships, and personal trauma or abuse in psychological risk and resilience.