Diagnostic agreement in the classification of headache using Ad Hoc Committee and IHS criteria.

This study examined the level of agreement between raters in the diagnosis of headache using the Ad Hoc Committee (AHC) on the Classification of Headache and the Headache Classification Committee of the International Headache Society (IHS) classification criteria. In addition, differences in classification of headache between the AHC and IHS classification systems were considered. Analyses indicated that both the AHC and IHS classification systems were adequate in allowing clinicians to reach 100% agreement in diagnosis of headache cases (N = 36). Additionally, there was 91.7% diagnostic agreement between the two sets of criteria as applied by the raters. Differences in diagnostic classification between the two sets of criteria were believed to be the result of IHS exclusionary criteria in the classification of Tension-type headache.