Limited agreement between criteria-based diagnoses of postconcussional syndrome

The objectives of this study were to compare diagnoses of postconcussional syndrome between the International Classification of Diseases, 10th revision (ICD-10) and Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV). The patient sample was comprised of 178 adults with mild-moderate traumatic brain injury (TBI). The study design was inception cohort, and the main outcome measure was a structured interview 3 months after injury. The results were that, despite concordance of DSM-IV and ICD-10 symptom criteria (kappa=0.73), agreement between overall DSM-IV and ICD-10 diagnoses was slight (kappa=0.13) because fewer patients met the DSM-IV cognitive deficit and clinical significance criteria. Agreement between DSM-IV postconcussional disorder and ICD-10 postconcussional syndrome appears limited by different prevalences and thresholds.