title: Chronic migraine and chronic daily headache in the Asia-Pacific region: a systematic review.
abstract: BACKGROUND
  Data on the prevalence and characteristics of chronic migraine (CM) and chronic daily headache (CDH) in the Asia-Pacific region are limited.
  
  
  METHODS
  We performed a systematic review on this topic, searching for studies published from 1996 to 2012 that reported the prevalence (population-based studies) or frequency (clinic studies) of CM or CDH. We calculated 95% confidence intervals for the prevalence in population studies. Results were qualitatively described.
  
  
  RESULTS
  Seven population studies and 19 hospital clinic studies from Asia were included. The CDH prevalence in population studies was 1.0-3.9% (median 2.9%). Only two studies from Taiwan reported the population prevalence of CM (1.0% and 1.7%). In addition, we derived a prevalence of 0.6% from a Malaysian study. Eleven clinic studies reported a CM frequency of 4.7-82% (median 52%) as a subset of CDH; classification of medication overuse varied. CM was associated with substantial disability.
  
  
  CONCLUSIONS
  The prevalence of CM and CDH in Asia appears lower than the global average, but applying the above prevalence estimates to the Asia-Pacific population would suggest that CM alone affects between 23 and 65 million individuals in the region.
authors.affiliation: Neurology Department, Alfred Hospital, Melbourne, Australia.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Stark
authors.forename: K
authors.initials: K
authors.lastname: Ravishankar
authors.forename: Hua Chiang
authors.initials: HC
authors.lastname: Siow
authors.forename: Kwang Soo
authors.initials: KS
authors.lastname: Lee
authors.forename: Rachael
authors.initials: R
authors.lastname: Pepperle
authors.forename: Shuu-Jiun
authors.initials: SJ
authors.lastname: Wang
mesh_terms: D001208:Asia / Q000453:epidemiology; D020773:Headache Disorders / Q000453:epidemiology*; D006801:Humans; D008881:Migraine Disorders / Q000453:epidemiology*; D010139:Pacific Islands / Q000453:epidemiology; D015995:Prevalence