Reliability and validity of the scales related to post traumatic stress disorder of Sri Lankan version

We attempted to measure symptomatic characteristics of PTSD in the victims of Tsunami disaster at Sri Lanka. At first, we develop the Harvard Traumatic Questionnaire (HTQ), Impact of the Event Scale Revised (IES-R), Hopkins Symptom Checklist (HCL) in Sri Lankan version for assessment. An expert in English and Sri Lankan translated these scales from English to Sri Lankan. Then, back-translation was done by a psychologist to check the difference between both versions. We administered these scales of the Sri Lankan version to 127 people who have been met with the Tsunami disaster [mean age = 39.0 (S.D. = 13.9)]. Psychometric properties of these scales were examined. Internal consistency as Cronbach's alpha of IES-R was 0.95. We determined if an individual met symptom criteria for the occurrence of PTSD according to a scoring algorithm proposed by the Harvard Refugee Trauma Group on the basis of DSM-4 diagnosis criteria derived from HTQ. We compared IES-R score of individual who has PTSD by HTQ with the score of non-PTSD. The difference was statistically significant by two-tailed t test (t = − 6.44, df = 1/84, p < 0.0001).