Psychometric evidence of the Impact of Events Scale (IES-6) in Peruvian adolescents

Introduction: symptoms of Post Traumatic Stress Disorder (PTSD) are a frequent public health problem in adolescent population. Empirical evidence shows that adverse events during adolescence can affect early adulthood and predict various psychological problems. Ongoing assessment of PTSD is essential for prevention and the availability of reliable, evidence-based psychological instruments is necessary. Objective: to analyze the psychometric properties of the Impact of Events Scale-6 (IES-6) in the general adolescent population. Methodology: we used an instrumental research, quantitative and cross-sectional approach. A total of 2877 adolescents from Huancavelica participated, who answered the IES-6 and other psychological instruments. Statistical analyses were performed with structural equation modeling and item response theory. Results: the IES-6 presents adequate evidence of content validity, unidimensional structure, reliability, measurement invariance according to sex and relationship with suicidal ideation, generalized anxiety and depression. Items 5 and 3 presented the highest discrimination and information, and the scale is accurate for high levels of PTSD. Conclusion: the IES-6 presents adequate sources of validity evidence and is a useful instrument for the assessment of PTSD symptoms in Peruvian adolescents. Its use is recommended in research and prevention and follow-up programs in public health and education.