Objectives: Post-traumatic stress disorder (PTSD) commonly co-occurs with chronic pain. Although PTSD symptoms are associated with negative health outcomes in patients with chronic pain, PTSD is typically under-detected and under-treated in outpatient pain settings. There is a need for rapid, brief screening tools to identify those at greatest risk for severe PTSD symptoms. To achieve that goal, our aim was to use item response theory (IRT) to identify the most informative PTSD symptoms characterizing severe PTSD in patients with chronic pain.
Methods: Fifty-six patients (71% female, 61% White) with mixed etiology chronic pain completed the PTSD Checklist-Civilian Version (PCL-C) as part of their appointment with a pain psychologist at a tertiary outpatient pain clinic. We used an IRT approach to evaluate each item's discriminant (a) and severity (b) parameters.
Results: Findings revealed that "feeling upset at reminders" (a = 3.67, b = 2.44) and "avoid thinking or talking about it" (a = 3.61, b = 2.17) as being highly discriminant for severe PTSD.
Conclusions: We identified 2 candidate items for a brief PTSD screener as they were associated with severe PTSD symptoms. These 2 items may provide clinical utility in outpatient pain treatment settings to identify those suffering from severe PTSD, enabling physicians to refer them to trauma-specific evaluation or therapy. Future research is needed to further validate and confirm these candidate PTSD items in a larger clinic sample.
Lay summary: The current study used the IRT approach to identify candidate items for a brief screener for severe PTSD. We examined 17 items of the PCL-C, and identified 2 items that were highly discriminant for severe PTSD. The 2 items were "feeling upset at reminders" and "avoid thinking or talking about it." These 2 items may provide clinical utility, since they may enable physicians to screen and make a referral for further assessment or treatment for PTSD.
Keywords: PTSD symptoms; a brief screener; chronic pain; item response theory.
© 2019 World Institute of Pain.