Psychometric Analysis of the PTSD Checklist for DSM-5 (PCL-5) in World Trade Center Responders: An Application of IRT Graded Response Model

Using IRT Graded Response Model, results from test information function indicated that the 20 items in the PCL-5 generally provide adequate information for the whole latent trait continuum, with the measurement providing 81.3% of the total information for high latent trait levels (above the mean).