The findings of a study in Psychological Medicine indicated that the proposed criteria for post-traumatic stress disorder in the 11th Revision of the International Classification of Disease (ICD-11) identified significantly fewer cases than the 10th Revision.
The new revision aims to make post-traumatic stress disorder a more specific diagnosis. Symptoms such as difficulty sleeping, poor concentration, irritability, and inability to recall an important aspect of the traumatic event would no longer be considered criteria for post-traumatic stress disorder. In ICD-11, dissociative flashbacks, hypervigilance, being easily startled, and avoidance of stimuli or memories associated with the event would characterize the disorder.
The investigators selected 11 longitudinal studies of post-traumatic stress disorder that comprised 3863 survivors, mostly of traffic accidents and other single traumatic incidents. The current and proposed diagnostic guidelines of CD-10 were applied to the Clinician-Administered PTSD Scale in patients at different time points between incident occurrence and 15 months following the incident.
ICD-11 criteria identified fewer cases than ICD-10 criteria across all assessment intervals from 0 to 456 days. Between 0 and 60 days, 24.89% of patients qualified for a diagnosis under ICD-10 criteria, while 12.94% did so under ICD-11 criteria. At the 122 to 456 day interval, those numbers decreased to 14.10% and 6.88% respectively. More than 97% of patients who received an ICD-11 diagnosis also received an ICD-10 diagnosis.
Symptom severity in patients who would be diagnosed under the updated criteria was between 31.38% and 36.49% higher than in patients who had met ICD-10 criteria alone. Cases diagnosed according to ICD-11 criteria were associated with similar or higher rates of comorbid mood and anxiety disorders.
Individuals who met either or both sets of criteria shortly after a traumatic event followed a similar longitudinal course across studies, and age and gender generally did not vary across revision.
The researchers stated that the interpretability of their findings may be limited, as patients in the original studies were not evaluated according to International Classification of Disease guidelines, but according to the Diagnostic and Statistical Manual of Mental Disorders. In addition, the study’s focus on single, sudden traumatic events might limit the generalizability of the outcomes to other forms of trauma.
Overall, the results demonstrated that the proposed revision was less likely to identify patients with mild to moderate post-traumatic stress disorder symptoms who might still require treatment. The investigators cautioned that use of the new criteria “to sanction access to care should be considered cautiously,” and that the criteria’s “utility for research should be empirically validated.”
Barbano A, van der Mei W, Bryant R, et al. Clinical implications of the proposed ICD-11 PTSD diagnostic criteria [published online May 14, 2018]. Psychological Medicine. https://doi.org/10.1017/S0033291718001101