Abstract
After two successful editions of the International Classification of Headache Disorders (ICHD), the third edition is now published. We call it ICHD-3 beta because it makes it possible to coordinate our classification with the forthcoming International Classification of Diseases edition 11 (ICD-11) of the World Health Organization (WHO). We have worked closely, and in parallel, with the WHO. This has resulted in a very good representation of headache in the draft version of ICD-11. Now the WHO wants field-testing for a couple of years and our classification can therefore be field-tested in parallel with the WHO version. This also allows us to “field-test” the ICHD-3 beta version in clinical practice; we expect few further refinements of the classification but they will not be revolutions. Thus, in two to three years we shall be able to publish not only ICHD-3 codes but also ICD-11 codes for all headache entities. That will make our classification much more useful because it is the WHO classification that in most countries is used for routine diagnostic coding. In many cases it also determines reimbursement for patient management. It is therefore of the utmost importance that the two classifications are congruent, although the ICHD-3 will remain more detailed than ICD 11.
We strongly recommend that everybody start using ICHD-3 beta immediately. Readers should not get confused by the “beta” labeling as this is solely required to link the ICHD-3 classification with the ICD-11, and we believe that only minor changes will take place. There are many important new aspects and many improvements in ICHD-3 beta. For example, the diagnostic criteria for chronic migraine are now part of the main body of the classification, and double coding is recommended for chronic migraine with medication overuse. There are completely revised criteria for the secondary headaches so that diagnostic coding is now possible at the first patient encounter. In the former edition a definite diagnosis could not be made until the patient had been cured or had substantially recovered from the causal disorder and from the secondary headache, which was highly impractical. A few new entities have been added either in the main body of the classification or in the appendix, which also has been considerably expanded. The appendix now contains alternative criteria for important entities such as migraine with aura and chronic migraine. Vestibular migraine has been defined in the appendix in a collaboration with the Barany Society in order to promote and facilitate research into this entity, which many consider prevalent and important, others not.
We also recommend translating ICHD-3 beta for e-publishing even if it may change somewhat in three years’ time. If the beta version is translated now, it will be very easy to make the modest changes that will be required after field-testing and to add ICD-11 code numbers. We also recommend that national headache societies publicize the publication of the ICHD-3 beta in their national-language journals. A comment, an editorial or something similar will probably interest the readership of national journals.
It has taken three and a half years to develop the ICHD-3 beta and the members of the classification committee have worked very hard to achieve it. As previously, there has been a working party for each chapter in the classification to which many additional headache experts have contributed significantly. I want to express my gratitude to the members of the classification committee and to all the many headache experts who have worked as members of the working parties.
Since the last edition of the ICHD, Marcia Wilkinson, Dieter Soyka and Frank Clifford Rose, who all were members of the first Classification Committee, are now deceased. We will always remember their important contributions to the classification of headache.
Finally, remember to cite ICHD-3 beta in your scientific papers. It is important to spread the knowledge about ICHD-3 beta and also to stimulate the use of this classification by experts and non-experts alike.