Validity of three PTSD scales in a sample of refugees and displaced persons

Three post-traumatic stress syndrome scales, Watson's PTSD questionnaire, and 39-item and 11-item Mississippi PTSD scale, were compared in the sample of 81 displaced persons from Croatia and refugees from Bosnia and Herzegovina. These were accommodated in two refugee settlements covered by the IRCT/Zagreb Help Project. The prevalence of PTSD in the group studied was 20% (Watson's PTSD questionnaire), 21.2 (39-item Mississippi scale), and 25% (11-item Mississippi scale). The internal consistency of the instruments, expressed as the coefficient alpha, was 0.9077 for the Watson's PTSD questionnaire, 0.9082 for the 39-item Mississippi scale, and 0.7863 for the 11-item Mississippi scale. There was also a high correlation between the three scales. The score on the two Mississippi scales were also in weak correlation with the intensity of trauma exposure measured by the Harvard trauma test. In conclusion, all three measuring instruments had suitable psychometric properties.The 11-item Mississippi scale may be suitable as an alternative to lengthier measuring instruments when the number of refugees is high and time is limited.