An item response theory analysis of the PTSD checklist for DSM-5: Implications for DSM-5 and ICD-11

An Item Response Theory Analysis of the Clinician-Administered PTSD Scale for DSM-5 Among Veterans

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.

Evaluating the Performance of the Primary Care Posttraumatic Stress Disorder Screen for DSM-5 (PC-PTSD-5) in a Trauma-Exposed, Socioeconomically Vulnerable Patient Population

The properties and utility of the Primary Care PTSD Screen for DSM-5 (PC-PTSD-5) remain unstudied in community-based populations. This study evaluates the performance of the PC-PTSD-5 to determine whether it can be used as a brief alternative to the PTSD Checklist for DSM-5 (PCL-5) in a large public hospital in the southeastern United States. Participants (N = 422; 92.7% Black; 85.8% female; Mage = 42.0 years, SDage = 13.4 years) completed the PCL-5 and PC-PTSD-5 after recruitment from medical clinic waiting rooms and admission lists. Using chance-corrected test quality indices and item response theory (IRT) analyses, we determined optimal cut-scores for screening and examined item performance. Approximately 45.0% of the sample screened positive for probable DSM-5 PTSD using the PCL-5. The PC-PTSD-5 demonstrated high internal consistency and strong associations with PCL-5 scores (total, r = .79; items, rs = .51-.61). A cut-score of one was optimally sensitive for screening (κ[1] = .96), and a cut-score of four had the highest quality of probable efficiency (κ[.5] = .66) for detecting self-reported DSM-5 PTSD on the PCL-5. IRT analyses indicated Item 1 (nightmares, intrusive memories) provided the most information, and other items may not be incrementally useful for this sample. Findings provide preliminary support for the use of the PC-PTSD-5 as a brief alternative to the PCL-5 among chronically trauma-exposed patients in the public healthcare setting.

Associations between DSM-5 posttraumatic stress disorder Criterion E2 endorsement and selected self-destructive behaviors in recent-era veterans: A focus on disordered eating

Revisions to the posttraumatic stress disorder (PTSD) criteria in the DSM-5 included a new criterion in the alterations in arousal and reactivity cluster (i.e., engagement in reckless and self-destructive behaviors; Criterion E2). Despite its clinical significance, little is known about how this symptom corresponds to engagement in specific direct and indirect self-harm behaviors. We examined associations between E2 and self-reported recent engagement in direct and indirect self-harm behaviors, including disordered eating, which is not included in the prototypical E2 symptom scope, in a trauma-exposed sample of 1,010 recent-era veterans (61.5% self-identified women, 38.5% self-identified men). We also tested whether gender moderated these associations. We repeated analyses in a subsample of participants with clinically elevated PTSD symptoms. Participants self-reported past-month PTSD symptoms (PCL-5) as well as past-month nonsuicidal self-injury, suicidal ideation, suicide planning, fasting, purging, binge eating, compulsive exercise, and problematic alcohol and drug use. We found no evidence for moderation by gender for any of the behaviors examined in the main sample. However, after controlling for gender and demographic covariates, weighted logistic regressions showed small, significant associations between E2 score and direct self-harm behaviors, substance use, purging, and binge eating, aORs = 1.30-1.91. Criterion E2 was linked to behaviors included in the typical symptom scope (self-directed violence, substance use) and those that are not (disordered eating behaviors). Comprehensive screening for self-destructive behaviors, including disordered eating, among veteran men and women who endorse Criterion E2 is indicated.

Differential symptom weighting in estimating empirical thresholds for underlying PTSD severity: Toward a "platinum" standard for diagnosis?

OBJECTIVE

Symptom counts as the basis for Post-Traumatic Stress Disorder (PTSD) diagnoses in the DSM presume each symptom is equally reflective of underlying disorder severity. However, the "equal weight" assumption fails to fit PTSD symptom data when tested. The present study developed an enhanced PTSD diagnosis based on (a) a conventional PTSD diagnosis from a clinical interview and (b) an empirical classification of full PTSD that reflected the relative clinical weights of each symptom.

METHOD

Baseline structured interview data from Project Harmony (N = 2658) was used. An enhanced diagnosis for full PTSD was estimated using an empirical threshold from moderated nonlinear factor analysis (MNLFA) latent PTSD scale scores, in combination with a full conventional PTSD diagnosis based on interview data.

RESULTS

One in 4 patients in the sample had a PTSD diagnosis that was inconsistent with their empirical PTSD grouping, such that the enhanced diagnostic standard reduced the diagnostic discrepancy rate by 20%. Veterans, and in particular female Veterans, were at greatest odds for discrepancy between their underlying PTSD severity and DSM diagnosis.

CONCLUSION

Psychometric methodologies that differentially weight symptoms can complement DSM criteria and may serve as a platform for symptom prioritization for diagnoses in future editions of DSM.

As simple as possible, but not simpler: Revisiting the International Trauma Questionnaire (ITQ) complex PTSD items omitted in the shortened version

BACKGROUND

The risks of oversimplification of the symptomatology of Complex PTSD (CPTSD) have been highlighted in the literature.

OBJECTIVE

To re-examine 10 items representing disturbances in self-organization (DSO) that were deleted from the original 28-item version of the International Trauma Questionnaire (ITQ) when creating the current 12-item version.

PARTICIPANTS AND SETTING

An online convenience sample of 1235 MTurk users.

METHODS

Online survey comprising the fuller 28-item previous version of the ITQ, Adverse Childhood Experiences (ACEs) questionnaire, and PTSD Checklist for DSM-5 (PCL-5).

RESULTS

First, averaged endorsement of the 10 omitted items was lower than the 6 retained DSO items (d' = 0.34). Second, the 10 omitted DSO items accounted for incremental variance over and correlated equivalently to the 6 retained items with the PCL-5. Third, only the 10 omitted DSO items (r_-part = 0.12) while not the 6 retained DSO items (r_-part = -0.01) independently predicted ACE scores and, eight of these ten omitted DSO items differentiated higher ACE scores even among the subset of 266 participants who endorsed all 6 of the retained DSO items, most with medium effect sizes. Fourth, exploratory principal axis factor analysis differentiated two latent variables within the fuller set of 16 DSO symptoms, with the strongest indicators of the second factor, namely uncontrollable anger, recklessness, derealization, and depersonalization, being unmeasured within the 6 retained DSO items. Moreover, scores on both factors independently predicted both PCL-5 and ACE scores.

CONCLUSIONS

There are conceptual and pragmatic advantages to revisiting a more content-valid and comprehensive conceptualization of CPTSD and DSO, partially as may be measured by the recently deleted items from the original and fuller length ITQ.

Measurement Error-Corrected Estimation of Clinically Significant Change Trajectories for Interventions Targeting Comorbid PTSD and Substance Use Disorders in OEF/OIF Veterans

In randomized control trials (RCTs), a focus on average differences between treatment arms often limits our understanding of whether individuals show clinically significant improvement or deterioration. The present study examined differences in individual-level clinical significance trajectories between Concurrent Treatment of PTSD and Substance Use Disorders Using Prolonged Exposure (COPE) and Relapse Prevention (RP). Eighty-one treatment-seeking veterans with a comorbid PTSD/SUD diagnosis were randomized to COPE or RP; data from an additional n = 48 patients who did not meet criteria for both disorders was used to establish a normative threshold. A newly developed, modernized approach to the Jacobson and Truax (1991) clinically significant change framework, using (a) moderated nonlinear factor analysis (MNLFA) scale scoring and (b) measurement error-corrected multilevel modeling (MEC-MLM) was used; this approach was compared to other approaches using conventional total scores and/or assuming no measurement error. Using a conventional approach to estimating the Reliable Change Index (RCI) yielded no differences between COPE and RP in the percentage of patients achieving statistically significant improvement (SSI; 88.9% for both groups). However, under MNLFA/MEC-MLM, higher percentages of patients receiving COPE (75.0%) achieved SSI compared to RP (40.7%). Findings suggest that, even though COPE and RP appear to reduce the same number of PTSD symptoms, MNLFA scoring of outcome measures gives greater weight to interventions that target and reduce "hallmark" PTSD symptoms.

Estimating posttraumatic stress disorder severity in the presence of differential item functioning across populations, comorbidities, and interview measures: Introduction to Project Harmony

Multiple factor analytic and item response theory studies have shown that items/symptoms vary in their relative clinical weights in structured interview measures for posttraumatic stress disorder (PTSD). Despite these findings, the use of total scores, which treat symptoms as though they are equally weighted, predominates in practice, with the consequence of undermining the precision of clinical decision-making. We conducted an integrative data analysis (IDA) study to harmonize PTSD structured interview data (i.e., recoding of items to a common symptom metric) from 25 studies (total N = 2,568). We aimed to identify (a) measurement noninvariance/differential item functioning (MNI/DIF) across multiple populations, psychiatric comorbidities, and interview measures simultaneously and (b) differences in inferences regarding underlying PTSD severity between scale scores estimated using moderated nonlinear factor analysis (MNLFA) and a total score analog model (TSA). Several predictors of MNI/DIF impacted effect size differences in underlying severity across scale scoring methods. Notably, we observed MNI/DIF substantial enough to bias inferences on underlying PTSD severity for two groups: African Americans and incarcerated women. The findings highlight two issues raised elsewhere in the PTSD psychometrics literature: (a) bias in characterizing underlying PTSD severity and individual-level treatment outcomes when the psychometric model underlying total scores fails to fit the data and (b) higher latent severity scores, on average, when using DSM-5 (net of MNI/DIF) criteria, by which multiple factors (e.g., Criterion A discordance across DSM editions, changes to the number/type of symptom clusters, changes to the symptoms themselves) may have impacted severity scoring for some patients.

Examining the psychometric properties of the PCL-5 in a black community sample using item response theory

Black Americans are more likely to be exposed to certain types of traumatic events and experience posttraumatic stress disorder (PTSD) compared to other racial groups. Consequently, sound assessment of PTSD in this underserved and understudied population is necessary to develop and accurately answer research questions about etiology and intervention efficacy. However, the item-level psychometric properties of one of the most commonly used assessment tools, the PTSD Checklist for DSM-5 (PCL-5), has yet to be examined among Black Americans. To address this gap, we used item response theory (IRT) to assess item difficulty and discrimination in a sample of Black American adults (n = 307). We employed a graded response model with all 20 items of the PCL-5 loading on to a latent PTSD factor. At clinically significant levels of PTSD, the most discriminating items were flashbacks, inability to experience positive emotions, and nightmares and the least discriminating items were cued emotional distress, diminished interest, and hypervigilance. These results emphasize the importance of flashbacks, inability to experience positive emotions, and nightmares and deemphasize the importance of hypervigilance and sleep difficulties when assessing for clinically significant symptoms of PTSD in Black Americans. Treatment implications include a nuanced approach towards hypervigilance.

Confirmatory factor analysis of the Clinician-Administered PTSD Scale (CAPS-5) based on DSM-5 vs. ICD-11 criteria

INTRODUCTION

Many studies have investigated the latent structure of the DSM-5 criteria for posttraumatic stress disorder (PTSD). However, most research on this topic was based on self-report data. We aimed to investigate the latent structure of PTSD based on a clinical interview, the Clinician-Administered PTSD Scale (CAPS-5).

METHOD

A clinical sample of 345 participants took part in this multi-centre study. Participants were assessed with the CAPS-5 and the Posttraumatic Stress Disorder Checklist (PCL-5). We evaluated eight competing models of DSM-5 PTSD symptoms and three competing models of ICD-11 PTSD symptoms.

RESULTS

The internal consistency of the CAPS-5 was replicated. In CFAs, the Anhedonia model emerged as the best fitting model within all tested DSM-5 models. However, when compared with the Anhedonia model, the non-nested ICD-11 model as a less complex three-factor solution showed better model fit indices.

DISCUSSION

We discuss the findings in the context of earlier empirical findings as well as theoretical models of PTSD.

The Development of a Sleep Intervention for Firefighters: The FIT-IN (Firefighter's Therapy for Insomnia and Nightmares) Study

Background: Firefighters are vulnerable to irregular sleep patterns and sleep disturbance due to work characteristics such as shift work and frequent dispatch. However, there are few studies investigating intervention targeting sleep for firefighters. This preliminary study aimed to develop and test a sleep intervention, namely FIT-IN (Firefighter’s Therapy for Insomnia and Nightmares), which was based on existing evidence-based treatment tailored to firefighters in consideration of their occupational characteristics. Methods: This study implemented a single-group pre-post study design, utilizing an intervention developed based on brief behavior therapy for insomnia with imagery rehearsal therapy components. FIT-IN consisted of a total of three sessions (two face-to-face group sessions and one telephone session). Participants were recruited from Korean fire stations, and a total of 39 firefighters participated. Participants completed a sleep diary for two weeks, as well as the following questionnaires to assess their sleep and psychological factors: insomnia severity index (ISI), disturbing dream and nightmare severity index (DDNSI), Epworth sleepiness scale (ESS), depressive symptom inventory-suicidality subscale (DSI), and Patient Health Questionnaire-9 (PHQ-9). These questionnaires were administered before the first session and at the end of the second session. Results: The FIT-IN program produced improvements in sleep indices. There was a significant increase in sleep efficiency (p < 0.01), and a decrease in sleep onset latency, number of awakenings, and time in bed (p < 0.05), as derived from weekly sleep diaries. In addition, significant decreases were shown for insomnia (p < 0.001) and nightmare severity (p < 0.01). Conclusion: There were significant improvements in sleep and other clinical indices (depression, PTSD scores) when comparing pre-and post-intervention scores. FIT-IN may be a feasible and practical option in alleviating sleep disturbance in this population. Further studies will be needed to ascertain FIT-IN’s effectiveness.