Primary headache disorders in the adult general population of Pakistan - a cross sectional nationwide prevalence survey

Background: The large geographical gaps in our knowledge of the prevalence and burden of headache disorders include almost all of Eastern Mediterranean Region (EMR). We report a nationwide population-based study in Pakistan, an EMR country with the sixth largest population in the world, conducted as a project within the Global Campaign against Headache. Methods: We surveyed six locations from the four provinces of Pakistan: Punjab, Sindh, Khyber Pakhtunkhwa and Baluchistan. We randomly selected and visited rural and urban households in each. One adult member (18-65 years) of each household, also randomly selected, was interviewed by a trained non-medical interviewer from the same location using a previously-validated structured questionnaire translated into Urdu, the national language. We estimated 1-year prevalences of the headache disorders of public-health importance and examined their associations with demographic variables using multivariate analysis. Results: There were 4223 participants (mean age 34.4 +/- 11.0 years; male 1957 [46.3%], female 2266 [53.7%]; urban 1443 [34.2%], rural 2780 [65.8%]). Participation proportion was 89.5%. Headache in the previous year was reported by 3233 (76.6% [95% CI: 75.3-77.8%]). The age-and gender-adjusted 1-year prevalence of migraine was 22.5% [21.2-23.8%] (male 18.0% [16.8-19.2%], female 26.9% [25.6-28.2%]), of tension-type headache (TTH) 44.6% [43.1-46.1%] (male 51.2% [49.7-52.7%], female 37.9% [36.4-39.4%]), of probable medication-overuse headache 0.7% [0.5-1.0%] (male 0.7% [0.5-1.0%], female 0.8% [0.5-1.1%]) and of other headache on >= 15 days/month 7.4% [6.6-8.2%] (male 4.4% [3.8-5.0%], female 10.4% [9.5-11.3%]). Migraine was more prevalent in females by a factor of 3: 2 although this association barely survived (P = 0.039) after correcting for other factors. TTH was more prevalent in males by about 4: 3 (P = 0.026). All headache and migraine were age-related, peaking in the age group 40-49 years; TTH peaked a decade earlier. Higher education (P = 0.004) and income (P = 0.001) were negatively associated with prevalence of migraine. Conclusion: With three quarters of its population affected, headache disorders must be on the public-health agenda of Pakistan. Worldwide, these disorders are the third leading cause of disability; information from specific enquiry into the burden attributable to headache disorders in this country is needed to inform health policy and priority-setting, and will be reported soon.