Accuracy of the Composite International Diagnostic Interview (CIDI 2.1) for diagnosis of post-traumatic stress disorder according to DSM-IV criteria

The objective was to study the accuracy of the post-traumatic stress disorder (PTSD) section of the Composite International Diagnostic Interview (CIDI 2.1) DSM-IV diagnosis, using the Structured Clinical Interview (SCID) as gold standard, and compare the ICD-10 and DSM IV classifications for PTSD. The CIDI was applied by trained lay interviewers and the SCID by a psychologist. The subjects were selected from a community and an outpatient program. A total of 67 subjects completed both assessments. Kappa coefficients for the ICD-10 and the DSM IV compared to the SCID diagnosis were 0.67 and 0.46 respectively. Validity for the DSM IV diagnosis was: sensitivity (51.5%), specificity (94.1%), positive predictive value (9.5%), negative predictive value (66.7%), misclassification rate (26.9%). The CIDI 2.1 demonstrated low validity coefficients for the diagnosis of PTSD using DSM IV criteria when compared to the SCID. The main source of discordance in this study was found to be the high probability of false-negative cases with regards to distress and impairment as well as to avoidance symptoms.