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Scoring and Psychometrics
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Scoring
Respondents rate each item from 1 ("not at all") to 5
("extremely") to indicate the degree to which they have been bothered by
that particular symptom over the past month. Thus, total possible scores
range from 17 to 85. Notwithstanding the fact that self-report scales
should not be used to make a formal diagnosis, the PCL has shown good
diagnostic utility, with Weathers et al. (1993) recommending a cut-off
score of 50 as optimal for indicating a probable diagnosis of
combat-related PTSD. An alternative strategy is to use individual items
according to the DSM criteria (i.e., at least one symptom from items 1 -
5, and at least three from items 6 - 12, and at least two from items 13
- 17). They suggest a cut off score of 3 or more for each item as being
most appropriate for this approach.
Psychometrics
The PCL has demonstrated strong psychometric properties.
Estimates of internal consistency (Cronbach's alpha) range between .94
(Blanchard et al, 1996) to .97 (Weathers et al. 1993) . Test-retest
reliability has been reported as .96 at 2-3 days and .88 at 1 week
(Blanchard et al.,1996; Ruggiero et al.,2003).
The PCL correlates positively with the Mississippi PTSD Scale with
convergent validity of between r = .85 and .93 (Weathers et al, 1993).
Strong correlations have also been reported with MMPI-2 Keane PTSD Scale
(.77), IES (.77-.90) and CAPS .92 (Blanchard et. al., 1996)
A cutoff score of 50 for a PTSD diagnosis has demonstrated good
sensitivity (.78 to .82) and specificity (.83 to .86). Lowering the
cutoff score to 44 revealed better sensitivity (.94), specificity (.86)
and overall diagnostic efficiency (.90) with MVA victims (Blanchard et.
al., 1996).
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| Non-English
Translations |
Bosnian (Charney et al, unpublished)
To our knowledge the Bosnian version is unpublished. Enquiries should be
directed to: Dr Meredith Charney, Department of Psychiatry,
Massachusetts General Hospital, Boston, MA mecharney@partners.org
Chinese (Wu et.al In Press)
The PCL has been translated in to traditional 'complex' Chinese (the
written Chinese used in Hong Kong and Taiwan), and simple Chinese
(the written Chinese used in Mainland China) . Wu etal tested the
psychometric properties in a sample of 481 survivors of motor vehicle
accidents. Reliability and validity of the Chinese PCL were found to be
satisfactory. The translation was validated by stringent
back-translation. Taking into consideration the difference in language
and culture, a bilingual clinical psychologist first translated the PCL
aiming at retaining the meaning of each item in the Chinese version.
Then an independent bilingual clinical psychologist back-translated the
translated PCL into English for content comparison. The content of the
final Chinese PCL was further verified by back-translation procedure
until the meaning of each item matched with the original item. For more
details see the paper or contact the author. Enquiries about the Chinese
version should be directed to: Dr Kitty Wu, Department of Clinical
Psychology, Caritas Medical Center, 111 Wing Hong Street, Shamshuipo,
Kowloon, Hong Kong, China. wukyk@ha.orh.hk
Spanish (Marshall, 2004; Orlando & Marshall,
2002)
The psychometrics of the Spanish PCL have been reported in detail in two
papers. They attest to the general equivalence of English and Spanish
language versions of the PCL as tools for measuring PTSD symptom
severity in Spanish and English speaking trauma survivors. When using
this version please note that the wording has been adjusted to enquire
about a specific trauma ('attack'). As a cautionary note, Orlando and
Marshall (2002) report that although the English and Spanish versions
are not fully equivalent on an item-by item basis, no bias was observed
at the level of composite PCL scale score, indicating that the 2
language versions are suitably similar for scale-level analyses (i.e the
total PCL score). The Spanish version was developed using double
translation procedures, detailed on page 52 of the 2002 paper. For
further information see the papers, or contact the authors: RAND 1776
Main Street, Santa Monica, CA USA 90407 Grant.marshall@rand.org
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Key/core References
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Blanchard, E. B., Jones Alexander, J., Buckley, T. C., &
Forneris, C. A. (1996). Psychometric properties of the PTSD Checklist
(PCL). Behaviour Research and Therapy, 34, 669-673.
Forbes, D., Creamer, M., & Biddle, D. (2001). The validity of the
PTSD checklist as a measure of symptomatic change in combat-related
PTSD. Behaviour Research & Therapy, 39, 977-986.
Ruggiero, K. J., Del Ben, K., Scotti, J. R., & Rabalais, A. E.
(2003). Psychometric Properties of the PTSD Checklist--Civilian Version.
Journal of Traumatic Stress, 16, 495-502.
Weathers, F. W., Litz, B. T., Herman, D. S., Huska, J. A., &
Keane, T. M. (1993). The PTSD Checklist (PCL): Reliability,
validity, and diagnostic utility. Paper presented at the 9th Annual
Conference of the ISTSS, San Antonio, TX.
Translations
Bosnian
Unpublished
Chinese
Wu, KK. et al (In press) Psychometric Properties and Confirmatory Factor
Analysis of the Posttraumatic Stress Disorder Checklist (PCL) for
Chinese Survivors of Motor Vehicle Accident Hong Kong Journal of
Psychiatry.
Spanish
Miles, J.V.C., Marshall, G.N., & Schell, T.S. (in
press). Spanish and English versions of the PTSD Checklist -
Civilian Version (PCL-C): Testing for differential item functioning.
Marshall, G. N. (2004). Posttraumatic stress disorder symptom
checklist: Factor structure and English-Spanish measurement invariance.
Journal of Traumatic Stress, 17(3), 223-23
Orlando, M., & Marshall, G. N. (2002). Differential item
functioning in a Spanish translation of the PTSD checklist: detection
and evaluation of impact. Psychological Assessment, 14(1),
50-59.
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