The Icelandic version of the PCL-5. Evidence for a one-dimensional model: A factor analytic study

Abstract

The PCL-5 (PTSD Checklist for DSM-5) is one of the most widely used instruments for assessing symptoms of posttraumatic stress disorder (PTSD). The measure consists of 20 questions that correspond to the PTSD symptoms in the DSM-5. Although its psychometric properties have been shown to be good to excellent with regard to reliability, convergent and divergent validity, the factor structure of the PCL-5 has remained less settled. Moreover, the instrument was translated from English to Icelandic in 2015, but the factor structure of this version has however not yet been examined. The study had both the local aim of determining the factor structure of the PCL-5’s Icelandic translation and a more general aim of casting light on the factor structure of the PCL-5. Participants were women from the SAGA Cohort (n=11,254), a nationwide study on the impact of trauma on women’s health. Exploratory factor analysis (EFA) was performed wherein several methods were used in a complementary manner to choose the number of factors. One factor was finally extracted. The factor had a relatively equal and strong influence to all 20 items on the PCL-5, suggesting that PTSD can be understood as a one-dimensional disorder. The results render support for measuring PTSD by way of a single sum score. A four-factor solution was also tested to see whether the factor loadings would reflect the DSM-5 model. The four-factor solution was cluttered and thus did not provide support for the DSM-5 diagnostic method of using four separate scores for each cluster.Efnisorð: Sálfræði, áfallastreituröskun, PCL-5