Assessing PTSD in the military: Validation of a scale distributed to Danish soldiers after deployment since 1998

Karen-Inge Karstoft; Søren B. Andersen; Anni Brit Sternhagen Nielsen

doi:10.1111/sjop.12360

Assessing PTSD in the military: Validation of a scale distributed to Danish soldiers after deployment since 1998

Karen-Inge Karstoft, Søren B. Andersen, Anni Brit Sternhagen Nielsen

11 Citations (Scopus)

Abstract

Since 1998, soldiers deployed to war zones with the Danish Defense (≈31,000) have been invited to fill out a questionnaire on post-mission reactions. This provides a unique data source for studying the psychological toll of war. Here, we validate a measure of PTSD-symptoms from the questionnaire. Soldiers from two cohorts deployed to Afghanistan with the International Security Assistance Force (ISAF) in 2009 (ISAF7, N = 334) and 2013 (ISAF15, N = 278) filled out a standard questionnaire (Psychological Reactions following International Missions, PRIM) concerning a range of post-deployment reactions including symptoms of PTSD (PRIM-PTSD). They also filled out a validated measure of PTSD-symptoms in DSM-IV, the PTSD-checklist (PCL). We tested reliability of PRIM-PTSD by estimating Cronbach's alpha, and tested validity by correlating items, clusters, and overall scale with corresponding items in the PCL. Furthermore, we conducted two confirmatory factor analytic models to test the factor structure of PRIM-PTSD, and tested measurement invariance of the selected model. Finally, we established a screening and a clinical cutoff score by application of ROC analysis. We found high internal consistency of the PRIM-PTSD (Cronbach's alpha = 0.88; both cohorts), strong item-item (0.48–0.83), item-cluster (0.43–0.72), cluster-cluster (0.71–0.82) and full-scale (0.86–0.88) correlations between PRIM-PTSD and PCL. The factor analyses showed adequate fit of a one-factor model, which was also found to display strong measurement invariance across cohorts. ROC curve analysis established cutoff scores for screening (sensitivity = 1, specificity = 0.93) and clinical use (sensitivity = 0.71, specificity = 0.98). In conclusion, we find that PRIM-PTSD is a valid measure for assessing PTSD-symptoms in Danish soldiers following deployment.

Original language	English
Journal	Scandinavian Journal of Psychology
Volume	58
Issue number	3
Pages (from-to)	260–268
Number of pages	9
ISSN	0036-5564
DOIs	https://doi.org/10.1111/sjop.12360
Publication status	Published - Jun 2017

Keywords

Faculty of Health and Medical Sciences
Item resonse theory
Rasch model
Depression
Military personnel
Psychometrics
Rasch decisions

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10.1111/sjop.12360

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title = "Assessing PTSD in the military: Validation of a scale distributed to Danish soldiers after deployment since 1998",

abstract = "Since 1998, soldiers deployed to war zones with the Danish Defense (≈31,000) have been invited to fill out a questionnaire on post-mission reactions. This provides a unique data source for studying the psychological toll of war. Here, we validate a measure of PTSD-symptoms from the questionnaire. Soldiers from two cohorts deployed to Afghanistan with the International Security Assistance Force (ISAF) in 2009 (ISAF7, N = 334) and 2013 (ISAF15, N = 278) filled out a standard questionnaire (Psychological Reactions following International Missions, PRIM) concerning a range of post-deployment reactions including symptoms of PTSD (PRIM-PTSD). They also filled out a validated measure of PTSD-symptoms in DSM-IV, the PTSD-checklist (PCL). We tested reliability of PRIM-PTSD by estimating Cronbach's alpha, and tested validity by correlating items, clusters, and overall scale with corresponding items in the PCL. Furthermore, we conducted two confirmatory factor analytic models to test the factor structure of PRIM-PTSD, and tested measurement invariance of the selected model. Finally, we established a screening and a clinical cutoff score by application of ROC analysis. We found high internal consistency of the PRIM-PTSD (Cronbach's alpha = 0.88; both cohorts), strong item-item (0.48–0.83), item-cluster (0.43–0.72), cluster-cluster (0.71–0.82) and full-scale (0.86–0.88) correlations between PRIM-PTSD and PCL. The factor analyses showed adequate fit of a one-factor model, which was also found to display strong measurement invariance across cohorts. ROC curve analysis established cutoff scores for screening (sensitivity = 1, specificity = 0.93) and clinical use (sensitivity = 0.71, specificity = 0.98). In conclusion, we find that PRIM-PTSD is a valid measure for assessing PTSD-symptoms in Danish soldiers following deployment.",

keywords = "Faculty of Health and Medical Sciences, PTSD, Screening, Assessment, Validation, Military, post-deployment mental health, Item resonse theory, Rasch model, Depression, Military personnel, Psychometrics, Rasch decisions",

author = "Karen-Inge Karstoft and Andersen, {S{\o}ren B.} and Nielsen, {Anni Brit Sternhagen}",

year = "2017",

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doi = "10.1111/sjop.12360",

language = "English",

volume = "58",

pages = "260–268",

journal = "Scandinavian Journal of Psychology",

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publisher = "The Scandinavian Psychological Associations",

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TY - JOUR

T1 - Assessing PTSD in the military

T2 - Validation of a scale distributed to Danish soldiers after deployment since 1998

AU - Karstoft, Karen-Inge

AU - Andersen, Søren B.

AU - Nielsen, Anni Brit Sternhagen

PY - 2017/6

Y1 - 2017/6

N2 - Since 1998, soldiers deployed to war zones with the Danish Defense (≈31,000) have been invited to fill out a questionnaire on post-mission reactions. This provides a unique data source for studying the psychological toll of war. Here, we validate a measure of PTSD-symptoms from the questionnaire. Soldiers from two cohorts deployed to Afghanistan with the International Security Assistance Force (ISAF) in 2009 (ISAF7, N = 334) and 2013 (ISAF15, N = 278) filled out a standard questionnaire (Psychological Reactions following International Missions, PRIM) concerning a range of post-deployment reactions including symptoms of PTSD (PRIM-PTSD). They also filled out a validated measure of PTSD-symptoms in DSM-IV, the PTSD-checklist (PCL). We tested reliability of PRIM-PTSD by estimating Cronbach's alpha, and tested validity by correlating items, clusters, and overall scale with corresponding items in the PCL. Furthermore, we conducted two confirmatory factor analytic models to test the factor structure of PRIM-PTSD, and tested measurement invariance of the selected model. Finally, we established a screening and a clinical cutoff score by application of ROC analysis. We found high internal consistency of the PRIM-PTSD (Cronbach's alpha = 0.88; both cohorts), strong item-item (0.48–0.83), item-cluster (0.43–0.72), cluster-cluster (0.71–0.82) and full-scale (0.86–0.88) correlations between PRIM-PTSD and PCL. The factor analyses showed adequate fit of a one-factor model, which was also found to display strong measurement invariance across cohorts. ROC curve analysis established cutoff scores for screening (sensitivity = 1, specificity = 0.93) and clinical use (sensitivity = 0.71, specificity = 0.98). In conclusion, we find that PRIM-PTSD is a valid measure for assessing PTSD-symptoms in Danish soldiers following deployment.

AB - Since 1998, soldiers deployed to war zones with the Danish Defense (≈31,000) have been invited to fill out a questionnaire on post-mission reactions. This provides a unique data source for studying the psychological toll of war. Here, we validate a measure of PTSD-symptoms from the questionnaire. Soldiers from two cohorts deployed to Afghanistan with the International Security Assistance Force (ISAF) in 2009 (ISAF7, N = 334) and 2013 (ISAF15, N = 278) filled out a standard questionnaire (Psychological Reactions following International Missions, PRIM) concerning a range of post-deployment reactions including symptoms of PTSD (PRIM-PTSD). They also filled out a validated measure of PTSD-symptoms in DSM-IV, the PTSD-checklist (PCL). We tested reliability of PRIM-PTSD by estimating Cronbach's alpha, and tested validity by correlating items, clusters, and overall scale with corresponding items in the PCL. Furthermore, we conducted two confirmatory factor analytic models to test the factor structure of PRIM-PTSD, and tested measurement invariance of the selected model. Finally, we established a screening and a clinical cutoff score by application of ROC analysis. We found high internal consistency of the PRIM-PTSD (Cronbach's alpha = 0.88; both cohorts), strong item-item (0.48–0.83), item-cluster (0.43–0.72), cluster-cluster (0.71–0.82) and full-scale (0.86–0.88) correlations between PRIM-PTSD and PCL. The factor analyses showed adequate fit of a one-factor model, which was also found to display strong measurement invariance across cohorts. ROC curve analysis established cutoff scores for screening (sensitivity = 1, specificity = 0.93) and clinical use (sensitivity = 0.71, specificity = 0.98). In conclusion, we find that PRIM-PTSD is a valid measure for assessing PTSD-symptoms in Danish soldiers following deployment.

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KW - PTSD

KW - Screening

KW - Assessment

KW - Validation

KW - Military

KW - post-deployment mental health

KW - Item resonse theory

KW - Rasch model

KW - Depression

KW - Military personnel

KW - Psychometrics

KW - Rasch decisions

U2 - 10.1111/sjop.12360

DO - 10.1111/sjop.12360

M3 - Journal article

C2 - 28419465

SN - 0036-5564

VL - 58

SP - 260

EP - 268

JO - Scandinavian Journal of Psychology

JF - Scandinavian Journal of Psychology

IS - 3

ER -

Assessing PTSD in the military: Validation of a scale distributed to Danish soldiers after deployment since 1998

Abstract

Keywords

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