Familial occurrence of headache disorders: A population-based study in mainland China.

BACKGROUND: Headache disorders are highly prevalent worldwide, and familial occurrence and heredity are contributory factors attracting the interest of epidemiological researchers. Our purpose, in a large sample drawn nationwide from the Chinese general population, was to evaluate the frequency of similar headache in first-degree relatives (FDRs) of those with different headache types.

METHODS: This was a questionnaire-based nationwide cross-sectional door-to-door survey using cluster random-sampling, selecting one adult (18-65 years) per household. Headache was diagnosed by ICHD-II criteria. Participants with headache were asked whether or not any FDRs had similar headache to their own. Chi-squared test and multivariate logistic regression analysis were used to assess the strength and significance of associations.

RESULTS: Of 5041 survey participants (participation rate 94.1%), 1060 (21.0%) were diagnosed with headache (migraine 469 [9.3%], tension-type headache [TTH] 543 [10.8%], headache on ≥15 days/month 48 [0.95%]). From these, 31 were excluded because of missing data about FDRs, leaving 1029 for analysis (male 350 [mean age: 46.7±11.4years]; female 679 [mean age 46.3±11.2years]). Similar headache in one or more FDRs was reported by 22.2% (95% CI: 19.6-24.7%) overall, by 25.1% (21.1-29.1%) of those with migraine, by 19.1% (15.7-22.4%) with TTH and by 29.2% (16.3-42.0%) with headache on ≥15 days/month. The differences was significant between migraine and TTH (OR=1.4, p=0.023), but were not significant between headache on ≥15 days/month and TTH (OR=1.7, p=0.093), migraine and headache on ≥15 days/month (OR=1.2,p=0.534). In multivariate analysis: for migraine versus TTH,AOR=1.2 (p=0.015); for headache on ≥15 days/month versus TTH, AOR 2.3 (p=0.018).

CONCLUSION: Headache was highly prevalent in China and common among FDRs of those with any type of headache (headache on ≥15 days/month>migraine>TTH). Against the background of the general-population prevalence of each disorder, familial occurrence was a very highly influential factor in headache on ≥15 days/month. There are important implications in this for public health and education.