The Impact of Events Scale (IES) was originally developed
by Horowitz et al (1979) to monitor the main phenomena
of re-experiencing the traumatic event and of avoidance of
that event and the feelings to which it gave rise. Hence, this
15 item, four-point scale, has two subscales of Intrusion and
It was not originally designed to be used with children, but
it has been successfully used in a number of studies with
children aged 8 years and older. However, two separate
large scale studies (Yule’s of 334 adolescent survivors of
a shipping disaster, and Dyregrov’s of children in Croatia)
found that a number of items are misinterpreted by children.
These separate studies identied identical factor structures
of the IES and these were used to select eight items that best
reected the underlying factor structure and so produced a
shortened version – the IES-8 for children.
With the dominance of DSM-IV, Weiss and Marmar (1997),
working with adults, added items to reect symptoms of
increased physiological arousal, although Horowitz had
found that these did not form a separate factor. We also
decided to develop 5 items that were designed to reect
the 5 DSM-IV Cluster D symptoms of arousal. Thus the
present version is designed for use with children aged 8
years and above who are able to read independently. It
consists of 4 items measuring Intrusion, 4 items measuring
Avoidance and 5 items measuring Arousal – hence it is
called the CRIES-13.
The development of this instrument has been largely
undertaken by colleagues working under the auspices of
the Children and War Foundation which was established
to support good quality research studies into the effects of
war and disasters on children. Good studies require good,
accessible measures. We are most grateful to Dr Mardi
Horowitz for agreeing to allow us to make this version
freely available to clinicians and researchers through this
In making this children’s IES-13 freely available, all we
ask is that those who use it send us copies of their results
so that we can continue to improve the measure for the
benet of children.
We will make available copies of the instrument in
different languages as the scale is properly translated and
back-translated. Any clinician or researcher wishing to
make such a translation should get in touch with us rst in
case a translation is already underway.
The IES is self completed and can therefore be administered
in groups.
There are 8 items that are scored on a four-point scale:
Not at all = 0
Rarely = 1
Sometimes = 3
Often = 5
There are three sub-scales:
Intrusion = sum of items 1+4+8+9
Avoidance = sum of items 2+6+7+10
Arousal = sum of items 3+5+11+12+13
The layout has been designed so that scoring can be easily
done in the three columns on the right hand side. The total
for each sub-scale can be entered at the bottom of each
Evaluation and psychometric status
At this point in time (June 2003), only one published study
has used the 13-item version. Psychometric data relevant
to the reliability and validity of the 8-item version were
presented in Yule (1997). There, it was reported that the
total score on the 8-item IES correlated highly with the total
score on the 15-item version of which it was part (r = +.95,
P <. 001).
The two versions of IES correlated with a symptom
count based on the number of DSM symptoms present
in adolescents following an acute trauma as follows:
15-IES = 0.7551; 8-IES, r = 0.6970. Thus, on this
relatively independent measure, the short form still
correlates very highly and there is not too much attrition
with the shorter scale.
In an analysis of the scores of 87 survivors of the sinking of
the Jupiter, it was found that the 62 children who received a
DSM diagnosis of PTSD scored 26.0 on the 8-item version
while the 25 who did not reach DSM criteria for a diagnosis
of PTSD only scored 7.8 (P < 0.001). Using these data, it
was found that a combined score (Intrusion + Avoidance) of
17 or more misclassied fewer than 10% of the children.
The 13-item version was used in a survey of 2,976 children
aged 9-14 years who had experienced the war in Mostar,
Bosnia (Smith, Perrin, Dyregrov and Yule, 2002). The
scale was translated into Bosnian and back-translated by
a separate Bosnian speaker to establish its accuracy. No
major differences were found between boys and girls in
respect of the factors identied and so only the total results
are presented here.
The Scales had satisfactory internal consistency. Cronbach
alphas were as follows:
Intrusion = 0.70; Avoidance = 0.73; Arousal = 0.60;
Total = 0.80
The analysis revealed a three-factor solution corresponding
to the three hypothesised sub-scales. The solution
accounted for 49.3% of the total variance.
Despite the theoretical criticisms often made against using
such self-completed scales in different cultures, the IES
has now been applied in a variety of cultures, including
studies with children. It is now clear that posttraumatic
stress symptoms in children are more similar across cultures
than they are different. Indeed, Intrusion and Arousal are
robust factors of the Impact of Event Scale in children from
different cultures.
We remind people using the scales that one cannot make a
clinical diagnosis from scores on the self-completed scales
alone. A proper clinical diagnosis relies on much more
detailed information obtained from a structured interview
that assesses not only the presence and severity of stress
symptoms, but also the impact on the child’s overall social
At present, there are no studies that have used the IES-13
and validated it against an independent clinical diagnosis.
Therefore, for screening purposes we recommend that
people use the results from the Intrusion and Avoidance
scales only. If the sum of the scores on these two scales is
17 or more, then the probability is very high that that child
will obtain a diagnosis of PTSD.
Dyregrov, A., Kuterovac, G. & Barath, A.(1996) Factor
analysis of the Impact of Event Scale with children in war.
Scandinavian Journal of Psychology, 36, 339-350.
Horowitz, M. J., Wilner, N., and Alvarez, W. (1979). Impact
of event scale: A measure of subjective stress. Psychosom.
Med., 41, 209-218
Kuterovac, G., Dyregrov, A.& Stuvland, R. (1994) Children
in war: A silent majority under stress. British Journal of
Medical Psychology, 67, 363-375.
Smith, P., Perrin, S., Dyregrov, A. & Yule, W. (2002)
Principal components analysis of the Impact of Event Scale
with children in war. Personality and Individual Differences,
Weiss, D. S., & Marmar, C. R. (1997). The impact of
event scale-revised. In J. P. Wilson, & T. M. Keane (Eds.),
Assessing Psychological Trauma and PTSD. New York: The
Guilford Press.
Yule, W. (1992) Post Traumatic stress disorder in child
survivors of shipping disasters: The sinking of the “Jupiter”.
J. Psychother. Psychosomatics, 57, 200-205.
Yule, W. (1997) Anxiety, Depression and Post-Traumatic
Stress in Childhood. In I. Sclare (Ed) Child Psychology
Portfolio. Windsor: NFER-Nelson
Yule, W., Ten Bruggencate, S & Joseph, S. (1994) Principal
components analysis of the Impact of Event Scale in
children who survived a shipping disaster. Personality and
Individual Differences, 16, 685-691.
Ofce use only
Not at
Rarely Some-
In Av Ar
1. Do you think about it even when you don’t mean to? [ ] [ ] [ ] [ ]
2. Do you try to remove it from your memory [ ] [ ] [ ] [ ]
Do you have difculties paying attention or
[ ] [ ] [ ] [ ]
4. Do you have waves of strong feelings about it [ ] [ ] [ ] [ ]
Do you startle more easily or feel more nervous
than you did before it happened?
[ ] [ ] [ ] [ ]
Do you stay away from reminders of it (e.g. places
or situations)
[ ] [ ] [ ] [ ]
7. Do you try not talk about it [ ] [ ] [ ] [ ]
8. Do pictures about it pop into your mind? [ ] [ ] [ ] [ ]
9. Do other things keep making you think about it? [ ] [ ] [ ] [ ]
10. Do you try not to think about it? [ ] [ ] [ ] [ ]
11. Do you get easily irritable [ ] [ ] [ ] [ ]
Are you alert and watchful even when there is no
obvious need to be?
[ ] [ ] [ ] [ ]
13. Do you have sleep problems? [ ] [ ] [ ] [ ]
© Children and War Foundation, 1998
Revised Child Impact of Event Scale
Below is a list of comments made by people after stressful life Event. Please tick each item showing how frequently these
comments were true for you during the past seven days. If they did not occur during that time please tick the ‘not at all’ box.
Name: …………………………………………………………………………… Date: ………………………………………
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