An item response theory analysis of the clinician-administered PTSD scale for DSM-5 among Veterans

Abstract: We used item response theory (IRT) analysis to examine Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) item performance using data from three large samples of veterans (total N = 808) using both binary and ordinal rating methods. Relative to binary ratings, ordinal ratings provided good coverage from well below to well above average within each symptom cluster. However, coverage varied by cluster, and item difficulties were unevenly distributed within each cluster, with numerous instances of redundancy. For both binary and ordinal scores, flashbacks, dissociative amnesia, and self-destructive behavior items showed a pattern of high difficulty but relatively poor discrimination. Results indicate that CAPS-5 ordinal ratings provide good severity coverage and that most items accurately differentiated between participants by severity. Observed uneven distribution and redundancy in item difficulty suggest there is opportunity to create an abbreviated version of the CAPS-5 for determining PTSD symptom severity, but not DSM-5 PTSD diagnosis, without sacrificing precision.

Read the full article
Report a problem with this article

Related articles

  • More for Researchers

    The impact of exposure to morally injurious events on posttraumatic stress symptoms among Israeli combat Veterans: a longitudinal moderated mediation model of moral injury outcomes and dispositional forgiveness

    Abstract: Background: Exposure to potentially morally injurious events (PMIEs) during military service can lead to moral injury (MI) outcomes and posttraumatic stress symptoms (PTSS). This longitudinal study examined the relationships between PMIE exposure, MI outcomes, and PTSS among Israeli combat veterans, and the potential protective role of dispositional forgiveness in these associations. Method: Participants were 169 Israeli combat veterans who participated in a six-year longitudinal study with four measurement points (T1: 12 months before enlistment, T2: Six months following enlistment- pre-deployment, T3: 18 months following enlistment- post-deployment, and T4: 28 months following discharge). Participants’ characteristics were assessed via semi-structured interviews (T1) and validated self-report measures (T2-T4) between 2019-2024. Results: Approximately 36% of participants reported exposure to PMIEs during service, with 13% exceeding the clinical threshold for probable PTSD at T4. PMIE-Betrayal at T3 was positively associated with MI outcomes of shame and trust violation at T4. The indirect effect of PMIEs on PTSS through MI outcome-Shame depended on forgiveness levels. Among veterans with low forgiveness, higher exposure to PMIE-Betrayal was associated with increased MI shame, which was linked to more severe PTSS. Conversely, for those with high forgiveness, exposure to PMIE-Self and Other was associated with decreased MI shame and subsequently reduced PTSS. Conclusion: Dispositional forgiveness moderates the relationship between PMIE exposure and MI outcomes, particularly shame, which mediates the development of PTSS. These findings highlight forgiveness as a potential target for intervention in treating moral injury and preventing PTSS among combat veterans.

    Mental Health Peer reviewed