You DS, et al. - Realizing the need for rapid, brief screening tools to identify patients with chronic pain at the greatest risk for severe PTSD symptoms, researchers investigated the most informative PTSD symptoms characterizing severe PTSD in patients with chronic pain. They used item response theory (IRT) for this purpose. At a tertiary outpatient pain clinic, they recruited 56 patients with mixed etiology chronic pain to complete the PTSD Checklist-Civilian Version as part of their appointment with a pain psychologist. Findings suggest that, for severe PTSD, “feeling upset at reminders” and “avoid thinking or talking about it” are highly discriminant. These two items may assist physicians in screening and referring patients for further assessment or treatment for PTSD.