How to quantify exposure to traumatic stress? Reliability and predictive validity of measures for cumulative trauma exposure in a post-conflict population

Abstract

Background

While studies with survivors of single traumatic experiences highlight individual response variation following trauma, research from conflict regions shows that almost everyone develops posttraumatic stress disorder (PTSD) if trauma exposure reaches extreme levels. Therefore, evaluating the effects of cumulative trauma exposure is of utmost importance in studies investigating risk factors for PTSD. Yet, little research has been devoted to evaluate how this important environmental risk factor can be best quantified.

Methods

We investigated the retest reliability and predictive validity of different trauma measures in a sample of 227 Ugandan rebel war survivors. Trauma exposure was modeled as the number of traumatic event types experienced or as a score considering traumatic event frequencies. In addition, we investigated whether age at trauma exposure can be reliably measured and improves PTSD risk prediction.

Results

All trauma measures showed good reliability. While prediction of lifetime PTSD was most accurate from the number of different traumatic event types experienced, inclusion of event frequencies slightly improved the prediction of current PTSD.

Conclusions

As assessing the number of traumatic events experienced is the least stressful and time-consuming assessment and leads to the best prediction of lifetime PTSD, we recommend this measure for research on PTSD etiology.

• Cumulative trauma exposure
• event list
• reliability
• predictive validity
• posttraumatic stress disorder

For the abstract or full text in other languages and supplementary material for this article, please see Supplementary files under ‘Article Tools’

For the abstract or full text in other languages and supplementary material for this article, please see Supplementary files under ‘Article Tools’

Authors’ contributions

ITK and SW designed the study. SW and AP constituted the study setup with support from ITK and TE. The data collection was accomplished by SW. Data preparation was performed by SW and DK. SW performed the statistical analyses, with essential contributions from SK. SW drafted the manuscript. All authors read and critically revised the manuscript and approved the final version of the paper for submission.

Acknowledgements

This study was supported by the German Research Society (Deutsche Forschungsgemeinschaft, DFG) and by a scholarship of the German National Academic Foundation (Studienstiftung des deutschen Volkes) awarded to SW. We thank the team of Ugandan therapists for conducting diagnostic interviews with the highest professionalism and empathy.

Conflict of interest and funding

All authors declare no conflict of interest.

Notes

For the abstract or full text in other languages and supplementary material for this article, please see Supplementary files under ‘Article Tools’