Preliminary Evaluation of the Psychometric Properties of the PTSD Checklist for DSM – 5

Abstract

Cognitive Behavioral Therapy relies on accurate assessment to provide efficacious treatment.
Post Traumatic Stress Disorder (PTSD) has evolved in the Diagnostic and Statistical Manual of
Mental Disorders Fifth Edition (DSM-­5), most notably with the addition of the negative
cognitions criterion category. The PTSD Checklist (PCL) is a validated self-­report screen for
PTSD that provides both diagnostic and symptom severity assessment. The PCL-­5 is an
updated version with new items that correspond to the recent changes. Prior research on the
PCL has been limited in its focus to military, clinical, and predominantly male samples, largely
ignoring other high risk populations. Public health estimates report significant trauma as high as
50 – 70% in college aged non-­clinical samples, with females at increased risk. Social
psychological research posits that women are most likely to be the targets of interpersonal
violence and sexual assault. Therefore, we evaluated the PCL-­5 in a largely female sample of
undergraduates. To our knowledge, this study is the first to report on the psychometric
properties and validity of the PCL-­5. A sample of 1093 participants (437 men, 656 women)
enrolled in introductory psychology courses at a large public university in the northeastern
United States completed the PCL-­5 in 2014. Using all 20 items of the PCL-­5, a principle
component analysis indicated a single factor (Eigen value = 12.2) that accounted for 61% of the
variance. Item loadings onto the single component ranged from .40 to .72. Cronbach’s alpha
indicated high internal consistency for this scale (α =.97). For each of the criterion subscales,
principle component analysis indicated a single factor that accounted for the variance. The
variance accounted for in the subscales ranged from 66% to 91%. Cronbach’s alpha indicated
high internal consistency for all of the criterion subscales ranging from α = .86 to α = .93. Using
the symptom severity scoring method with cut point of 38 put forth by the National Center for
PTSD, 8.5% (n = 93) of the sample met criteria for PTSD. Using the diagnostic scoring
algorithm proposed by the National Center for PTSD, 10.8% (n = 131) of the sample met DSM
5 diagnostic criteria. The latter method resulted in a higher estimate of the prevalence of PTSD,
but the two estimates were not significantly different from one-­another (χ2 = 3.2, p=0.07). We
compared these results to a separate sample of 1,439 students (424 men, 1005 women) also
drawn from introductory psychology courses at the same university who completed the PCL-­C
in 2013. Results for both symptom severity and diagnostic assessment using the PCL-­C were
not significantly different from PCL-­5 results. Finally, we found the women in our sample
showed an elevation of PTSD symptoms relative to men. This study drew on existing research
from other social sciences in order to address the need for the assessment of PTSD in women.
Our results provide preliminary evidence for the PCL-­5 as an assessment to measure PTSD
utilizing DSM-­5 criteria. Future research should evaluate the PCL-­5 in clinical populations and
further test the measure’s psychometric properties. The accurate detection of individuals with
PTSD is critical in order to provide the appropriate treatment.

Full text

Preliminary Evaluation of the Psychometric Properties
of the PTSD Checklist for DSM – 5
Jeffrey Cohen1, Nitya Kanuri2, Dustin Kieschnick1, Christine Blasey1,2, C. Barr Taylor2, Eric Kuhn3,
Caroline Lavoie1, Danielle M. Ryu1,2, Elise Gibbs1, Josef Ruzek3, & Michelle G. Newman4
PGSP – Stanford University PsyD Consortium1, Stanford University Medical Center2, VA National Center for PTSD2 , & The Pennsylvania State University4
Method'
A sample of 2490 participants (805 men, 1,679 women, 3 transgender ) enrolled in
introductory psychology courses in the northeastern United States completed the PCL-5 in 2014.
Two clinical psychology graduate students independently coded the experiences reported
by participants as traumatic or not according to DSM-5 criteria resulting in n = 248 (176 women,
73 men) of participants exposed to trauma. Agreement between raters was high (kappa = .88).
Using the 10% of participants with trauma exposure (n = 248), principle component analysis
was used to derive factors, loadings of each item onto factors, and internal consistency for the
four PCL-5 criterion subscales. Both symptom severity and the diagnostic classification scoring
were assessed, as well as the association between the two.
• Criterion B (Re-experiencing)
A single factor accounted for 71% of the variance (Eigenvalue = 3.5). Item loadings ranged
from .82 to .89. Cronbach's α =.89
• Criterion C (Avoidance)
A single factor accounted for 92% of the variance (Eigenvalue = 1.84). Item loadings were
.96 for both items. Cronbach’s α =.91
• Criterion D (Negative Alterations in Cognition and Mood)
A single factor accounted for 65% of the variance (Eigenvalue = 4.53). Item loadings ranged
from .67 to .87. α =.91
• Criterion E (Hyper-Arousal)
A single factor accounted for 60% of the variance (Eigenvalue = 3.61). Item loadings ranged
from .79 to .82. Cronbach’s α =.87
Results'
Introduc0on'
The definition of Post Traumatic Stress Disorder (PTSD) has
evolved in the Diagnostic and Statistical Manual of Mental Disorders
Fifth Edition (DSM-5). The revised Criterion A delineates what
comprises a traumatic event and removes the previous requirement
of an emotional response of “fear, helplessness, or horror.” The
symptoms of PTSD expanded from the three diagnostic clusters in
the Diagnostic and Statistical Manual of Mental Disorders Fourth
Edition (DSM-IV-TR) to four behavioral clusters in DSM-5. The newly
added cluster, negative alterations in cognition and mood, joins the
DSM-IV-TR clusters of re-experiencing, avoidance, and arousal.
The PTSD Checklist (PCL) is a self-report screen for PTSD,
which can be scored for both diagnostic assessment and symptom
severity measurement. The PCL-5 is an updated version of the
questionnaire that includes 3 new items which correspond to the
new DSM-5 negative alteration in cognition and mood criterion
category. Additionally, the PCL-5 limits the scope of the assessment
to the “past week,” whereas prior versions of the PCL assessed
symptoms over the past month.
Previous versions of the PCL include the PTSD Checklist-
Military (PCL-M), PTSD Checklist-Civilian (PCL-C), and the PTSD
Checklist-Specific (PCL-S). Similar to the PCL-S, the PCL-5 prompts
participants to identify a specific traumatic event at the start of the
self-report measure.
Research on previous versions of PCL is limited to military,
clinical, and predominantly male samples. While the focus on the
aforementioned population is warranted given their known exposure
to major trauma, other high risk populations, such as female victims
of interpersonal violence, have been largely ignored.
The present study may be the first to estimate basic
psychometric properties of the PCL-5 as an assessment to screen
for PTSD. We evaluated the PCL-5 in a non-clinical, civilian
population comprised of 67% women.
Discussion'
• All four criterion scales of the PCL-5 had high internal
consistency.
• For this sample of college students, survivors of sexual and
physical assault reported the most severe PTSD
symptomatology.
• Both the diagnostic algorithm and the symptom severity cut
point scoring produced comparable results, suggesting
evidence of concurrent validity for both methods.
This is a first step in establishing psychometric and clinical utility
of the PCL-5. Future studies will include testing a four factor
versus five factor model of PTSD (Elhai et al., 2011).
Shown in the figure below:
• 1.4% (36/2490) of the total sample met DSM-5 diagnostic criteria
for PTSD using the diagnostic algorithm of the PCL-5.
• 1.3% (32/2490) met criteria for PTSD using the cut-point
suggested by the National Center of PTSD (i.e, >38). For the
cut point of 38, the sensitivity was .78 and specificity was .98.
References
American Psychiatric Association (2013). Diagnostic and Statistical Manual Of Mental Disorders (5th ed.). Arlington, VA:
American Psychiatric Publishing.
Elhai, J. D., & Palmieri, P. A. (2011). The factor structure of posttraumatic stress disorder: A literature update, critique of
methodology, and agenda for future research. Journal of Anxiety Disorders, 25(6), 849-854.
Weathers, F.W., Litz, B.T., Keane, T.M., Palmieri, P.A., Marx, B.P., & Schnurr, P.P. (2013).The PTSD Checklist for DSM-5 (PCL-5)
Results'(con0nued)'
Shown in the table below are the traumas reported by the
participants and the mean PCL- 5 scores. The highest severity of
symptoms was reported by victims of sexual assault.
Denotes new items to PCL-5
1.4% 1.3%
0%
1%
2%
3%
4%
5%
Diagnostic Algorithm Symptom Severity
PTSD Prevalence in Sample
PCL-5 Items
20.$Trouble$falling$or$staying$asleep?
9.$Having$strong$negative$beliefs$about$yourself,$other$people,$or$the$world$
(for$example,$having$thoughts$such$as:$I$am$bad,$there$is$something$seriously$
wrong$with$me,$no$one$can$be$trusted,$the$world$is$completely$dangerous)?
10.$Blaming$yourself$or$someone$else$for$the$stressful$experience$or$what$
happened$after$it?
11.$Having$strong$negative$feelings$such$as$fear,$horror,$anger,$guilt,$or$
shame?
12.$Loss$of$interest$in$activities$that$you$used$to$enjoy?
13.$Feeling$distant$or$cut$off$from$other$people?
14.$Having$trouble$experiencing$positive$feelings$(for$example,$being$unable$
to$feel$happinenss$or$having$loving$feelings$for$people$close$to$you)?
15.$Feeling$irritable$or$angry$or$acting$aggressively?
16.$Taking$too$many$risks$or$doing$things$that$could$cause$you$harm?
17.$Being$"superalert"$or$watchful$or$on$guard?
18.$Feeling$jumpy$or$easily$startled?
19.$Having$difficulty$concentrating?
8.$Trouble$remembering$important$parts$of$the$stressful$experience?
In$the$past$week,$how$much$were$you$bothered$by:
1.$Repeated,$disturbing,$and$unwanted$memories$of$the$stressful$
experience?
2.$Repeated,$disturbing$dreams$of$the$stressful$experience?
3.$Suddenly$feeling$or$acting$as$if$the$stressful$experience$were$atually$
happening$again$(as$if$you$were$actuallly$back$there$reliving$it)?
4.$Feeling$very$upset$when$something$reminded$you$of$the$stressful$
experience?
5.$Having$strong$physical$reactions$when$something$reminded$you$of$the$
stressful$experience$(for$example,$heart$pounding,$trouble$breathing,$
sweating)?
6.$Avoiding$memories,$thoughts,$or$feelings$related$to$the$stressful$
experience?
7.$Avoiding$external$reminders$of$the$stressful$experience$(for$example,$
people,$places,$conversations,$activities,$objects,$or$situations)?