Application of ICHD-II criteria in a headache clinic of China.

backgroundChina has the huge map and the largest population in the world. Previous studies on the prevalence and classification of headaches were conducted based on the general population, however, similar studies among the Chinese outpatient population are scarce. This study aimed to analyze the characteristics of 1843 headache patients enrolled in a North China headache clinic of the General Hospital for Chinese People's Liberation Army from October 2011 to May 2012, with the International Classification of Headache Disorders, 2nd Edition (ICHD-II). METHODS AND

resultsPersonal interviews were carried out and a detailed questionnaire was used to collect medical records including age, sex and headache characteristics. Patients came from 28 regions of China with the median age of 40.9 (9-80) years and the female/male ratio of 1.67/1. The primary headaches (78.4%) were classified as the following: migraine (39.1%), tension-type headache (32.5%), trigeminal autonomic cephalalgias (5.3%) and other primary headache (1.5%). Among the rest patients, 12.9% were secondary headaches, 5.9% were cranial neuralgias and 2.5% were unspecified or not elsewhere classified. Fourteen point nine percent (275/1843) were given an additional diagnosis of chronic daily headache, including medication-overuse headache (MOH, 49.5%), chronic tension-type headache (CTTH, 32.7%) and chronic migraine (CM, 13.5%). The visual analogue scale (VAS) score of TTH with MOH was significantly higher than that of CTTH (6.8±2.0 vs 5.6±2.0, P<0.001). The similar result was also observed in VAS score between migraine with MOH and CM (8.0±1.5 vs 7.0±1.5, P = 0.004). The peak age at onset of TTH for male and female were both in the 3(rd) decade of life. However, the age distribution at onset of migraine shows an obvious sex difference, i.e. the 2(nd) decade for females and the 1(st) decade for males. CONCLUSIONS/SIGNIFICANCE: This study revealed the characteristics of the headache clinic outpatients in a tertiary hospital of North China that migraine is the most common diagnosis. Furthermore, most headaches in this patient population can be classified using ICHD-II criteria.