Diagnostic screen for assessment of the IHS criteria for migraine by general practitioners.

This study examines the sensitivity and specificity of a self-report screen for the diagnosis of migraine according to the IHS criteria in a sample of 1049 employees of the French National Railways. The diagnosis of migraine derived from the self-report instrument was compared to an unstructured diagnostic interview conducted by a neurologist specialized in the diagnosis and treatment of headache. The sensitivity of the diagnostic screen was poor, but the specificity was excellent. Optimal cut-off points for the questionnaire were determined by the Receiver Operator Characteristics (ROC) method. Assessment of the specific IHS criteria for migraine revealed that the following criteria failed to discriminate subjects with migraine from non-cases: "aggravation by physical activity" and "photophobia and phonophobia". Implications of the findings for modification of the IHS criteria were discussed.