The impact of item order on the factor structure of the PTSD Checklist for DSM-5.

The PTSD Checklist for DSM-5 (PCL-5) is the most widely used self-report measure of posttraumatic stress disorder (PTSD) and is frequently modeled as having four correlated factors consistent with the DSM-5 symptom structure. Some researchers have argued that item order may influence factor structure. Although two studies have examined this, they were both based on DSM-IV criteria, and neither utilized a randomized design.