Psychometric Properties of the Impact of Events Scale-Revised (IES-R) Among General Iranian Population During the COVID-19 Pandemic

Sharif Nia, Hamid; Kaur, Harpaljit; Fomani, Fatemeh Khoshnavay; Rahmatpour, Pardis; Kaveh, Omolhoda; Pahlevan Sharif, Saeed; Venugopal, A. Vijayalakshmi; Hosseini, Lida

Objective: The aim of this study was to translate and evaluate the validity and reliability of the Impact of Events Scale-Revised (IES-R) among the Iranian general population during the coronavirus disease 2019 (COVID-19) pandemic. Method: This study was methodological cross-sectional. It was conducted on an Iranian public population from April to July 2020 which was during the COVID-19 pandemic. Construct validity was determined through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) with a total of 500 adults recruited via online data gathering. Reliability was checked through the average inter-item correlation (AIC), Cronbach's alpha, and McDonald's omega. Convergent and divergent validity was determined using Fornell and Larcker's approach. Results: The results showed that the Persian version of IES-R had three factors, including intrusion (six items), avoidance (seven items), and hyperarousal (five items), that explained 59.22% of the total variance of the IES-R. The CFA findings indicated that all goodness-of-fit indices confirmed the model fit. The Cronbach's alpha, McDonald's omega, composite reliability (CR), and maximal reliability were excellent, and the three factors have good convergent validity. Conclusion: The findings of this study indicated that the Persian version of the IES-R scale is efficient and useful to assess post-traumatic stress disorder among Iran general population in the COVID-19 outbreak.