Chronic daily headache in Taipei, Taiwan: prevalence, follow-up and outcome predictors

We conducted a two-stage population-based headache survey among subjects aged greater than or equal to15 in Taipei, Taiwan. Subjects with chronic daily headache (CDH) in the past year were identified, interviewed and followed-up. CDH was defined as a headache frequency >15 days/month, with a duration >4 h/day. Of the 3377 participants, 108 (3.2%) fulfilled the criteria for CDH, with a higher prevalence in women (43%) than men (1.90%). TM was the most common subtype (55%), followed by CTTH (44%). Thirty-four per cent of the CDH subjects overused analgesics. At the 2-year follow-up, 35% of the CDH subjects still had CDH. The significant predictors for persistent CDH it follow-up included: older age (greater than or equal to40 years) (RR=2.4), CDH onset after 32 years (RR=1.8), CDH duration greater than or equal to6 years (RR=2.0), medication overuse (RR=1.8), and 'daily' headache (RR=2.1). We found that CDH is not uncommon in the community and its prevalence is similar among different populations. Older subjects and those with medication overuse may have a more protracted course of illness.