Does Size really matter? A multisite study of competing diagnostic criteria

Clinicians and researchers are becoming increasingly aware of the difficult decision that they are likely to be making within the next years; deciding between the use of two rather different descriptions of the posttraumatic stress disorder (PTSD) diagnosis. The Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM-5), which describes PTSD as a diagnosis comprised of 20 symptoms belonging to four symptom clusters, and the World Health Organization’s proposed 11th revision of the International Classification of Diseases (ICD-11) set for release in 2018 in which PTSD is comprised by only 6-7 symptoms belonging to three symptom clusters. Numerous studies have supported the latent structure of PTSD according to different models of the DSM-5 and the ICD-11 proposal. The few studies investigating the ICD-11 and the DSM-5 in the same populations appear to suggest that the ICD-11 model may result in better fit than the DSM-5 based models. At the same time, there is also a tendency for ICD-11 to produce lower estimated PTSD prevalence rates than the DSM-5 criteria, which may ultimately affect who is offered treatment. Of note, it is important to stress that there is a lack of studies investigating the latent structure of the ICD-11 and DSM-5 models in the same populations using appreciate measurements of both the ICD-11 and the DSM-5 PTSD. At the same time, it is important to investigate this in different trauma populations as previous research suggest that differences in prevalence rates may only exist following specific types of traumatic exposure.
The aim of the present study was to investigate the latent structure of different ICD-11 and DSM-5 models of PTSD in three different trauma populations and
compare the estimated diagnostic rates of PTSD based on the DSM-5 and the ICD-11, respectively.