Exploration of cross-cultural adaptability of PTSD among trauma survivors in Northern Iraq, Thailand, and the Democratic Republic of Congo: Application of item response theory and classical test theory

Abstract

Background: There has been an ongoing debate in the trauma field regarding the validity of Post-Traumatic Stress Disorder (PTSD) as a construct among trauma-affected populations displaced from or living in non-Western, low and middle income countries. Some researchers argue that PTSD is a Western construct that is only relevant in Western settings, while others assert that PTSD may be a universal concept. Purpose: To determine if there are a core set of PTSD symptoms that are applicable across three non-Western low and middle income countries (LMIC). Methods: Secondary data analysis was conducted from baseline, screening and validity studies among torture survivors in Northern Iraq, sexual violence survivors in the Democratic Republic of Congo (DRC), and Burmese survivors of mass human rights violations in Thailand. Item response theory (IRT) and confirmatory factor analysis (CFA) was conducted to explore core PTSD symptoms. Results: Confirmatory factor analyses indicated that the best fitting model for the whole sample was a 4-factor "numbing" model (with effortful avoidance, arousal, numbing and intrusion factors). Results from the multidimensional IRT rating scale model indicated four core items across the whole sample. Accounting for multidimensionality with the "numbing" PTSD model, the four items were from the effortful avoidance and arousal domains. Results revealed that seven items demonstrated differential item functioning were from the re-experiencing, numbing, and arousal domains. All items demonstrated statistically significant differential item functioning but small to moderate effect size. Conclusions: Core items found across the three countries are indicative of culturally relevant items that are concrete in nature, as well as relatively easy to measure and operationalize. The small effect size in the potential DIF items suggests that there is little meaningful/clinical difference of the items across country for general screening of PTSD symptoms. However, in clinical settings where a specific assessment for culture is developed or utilized, DIF items should potentially be accounted for and analyzed as having item bias. In general, findings suggest that measurement PTSD has universal as well as country-specific aspects.