The heterogeneity of headache patients who self-medicate: a cluster analysis approach.

Patients with headache often self-treat their condition with over-the-counter analgesics. However, overuse of analgesics can cause medication-overuse headache. The present study aimed to identify subgroups of individuals with headache who self-medicate, as this could be helpful to tailor intervention strategies for prevention of medication-overuse headache. Patients (n = 1021) were recruited from 202 community pharmacies and completed a self-administered questionnaire. A hierarchical cluster analysis was used to group patients as a function of sociodemographics, pain, disability, and medication use for pain. Three patient clusters were identified. Cluster 1 (n = 498, 48.8%) consisted of relatively young individuals, and most of them suffered from migraine. They reported the least number of other pain complaints and the lowest prevalence of medication overuse (MO; 16%). Cluster 2 (n=301, 29.5%) included older persons with mainly non-migraine headache, a low disability, and on average pain in 2 other locations. Prevalence of MO was 40%. Cluster 3 (n=222, 21.7%) mostly consisted of patients with migraine who also report pain in many other locations. These patients reported a high disability and a severe limitation of activities. They also showed the highest rates of MO (73%).