Interrater reliability of the DSM-5 and ICD-11 Criterion A for PTSD and complex PTSD in parents of children with autism using the Life Events Checklist

Background Parents of children with autisma demonstrate elevated traumatic stress symptoms, but seldom receive diagnoses of post-traumatic stress disorder (PTSD) or complex PTSD. An accurate assessment of Criterion A is essential for a valid diagnosis of these disorders, yet it is uncertain whether Criterion A, as defined by the two primary international diagnostic systems (DSM-5-TR and ICD-11), yields consistent interrater reliability, when psychologists rely solely on self-report from these parents for assessing PTSD or complex PTSD. Aims This study aims to investigate interrater reliability across psychologists when assessing Criterion A events against the ICD-11 and DSM-5-TR. Method Ten Australian psychologists rated parents’ self-reported traumatic events related to parenting, using the Life Events Checklist for DSM-5-TR and ICD-11 Criterion A. Data from 200 randomly selected parents of children, all meeting symptom thresholds for PTSD or complex PTSD, were analysed. Bootstrapping calculated kappa coefficients, differences between ICD-11 and DSM-5-TR criteria, and self-reports of threat/no threat, with 95% confidence intervals for these differences. Results Interrater reliability varied from poor to moderate. The ICD-11 had significantly higher reliability than the DSM-5-TR for Criterion A (κdifference = 0.105, 95% CI 0.052–0.153, P < 0.001). The interrater reliability was lower when parents reported life threat, serious injury or death (κdifference = 0.096, 95% CI 0.019–0.176, P = 0.007). Conclusions This study highlights challenges in assessing PTSD and complex PTSD Criterion A in parents of children with autism, using DSM-5-TR and ICD-11 criteria with the Life Events Checklist, revealing less than adequate interrater reliability.