Medication-overuse headache in China: Clinical profile, and an evaluation of the ICHD-3 beta diagnostic criteria

Background Although medication-overuse headache (MOH) is common in China, its clinical profile is not yet fully established. Meanwhile, ICHD-3 beta has been published, but its diagnostic criteria require further validation. Methods We retrospectively classified the clinical features of 240 consecutive patients with MOH (55 males, 185 females), whose demographic data, headache features, overused medications (type, quantity, frequency and duration of use), headache-attributed burden, and outcomes were reviewed. We then applied the criteria of the several versions of ICHD (II, IIR and 3-beta) to these patients. Results Compared with those with other headaches, patients with MOH were more likely to be less well educated (64.6% vs 42.0% for secondary school or lower, p < 0.0001), and on lower annual incomes (72.3% vs 56.0% for an income of Chinese yuan (CNY) 30,000 or less, p < 0.0001). Combination analgesics were the most commonly overused medications, and, caffeine (89.9%), aminopyrine (70.0%), phenacetin (53.9%) and phenobarbital (48.8%) were the most commonly used specific components of these. Only two patients (0.8%) had previously been given the diagnosis of MOH; accordingly, the median time to diagnosis after the estimated onset of the disorder was 4.0 years. The majority of patients (83.7%) improved with treatment. All 240 patients fulfilled the diagnostic criteria for MOH according to ICHD-3 beta; only 134 (55.8%) satisfied the diagnostic criteria for definite MOH according to ICHD-II, while 195 (81.2%) met those of ICHD-IIR. Conclusions MOH in China is associated with lower educational level and annual income. MOH has rarely been diagnosed and correctly treated in China. ICHD-3 beta appears to be more appropriate for the diagnosis of MOH than previous versions.