Factors associated with disability and impact of tension-type headache: findings of the Korean headache survey

BACKGROUND: Although mostly mild in symptom severity, tension-type headache (TTH) can cause disability. However, factors associated with disability of TTH have been rarely reported. This study sought to assess the factors associated with TTH-related disability and impact. METHODS: We analyzed data form the Korean Headache Survey, a nation-wide survey regarding headache in all Korean adults aged 19–69 years. TTH-related disability was measured by surveying actual disability and Headache Impact Test-6 (HIT-6). Actual disability was defined as having one or more days of activity restriction or missed activity due to headache in the last 3 months. The HIT-6 score ≥ 50 was regarded as significant headache impact associated with TTH. We assessed factors associated with TTH-related disability and impact using logistic regression analyses adjusting for sociodemographic variables and headache characteristics. RESULTS: Among 1507 individuals, the 1-year prevalence rate of TTH was 30.7% (n = 463), of which 4.8% reported actual disability and 21.3% had headache impact, respectively. In univariate analyses, sociodemographic variables were not associated with actual disability and headache impact, respectively. There were relationships between several headache characteristics and actual disability/headache impact. After adjustment of potential confounders, moderate headache intensity was correlated with actual disability (odds ratio [OR]: 4.41, 95% confidence interval [CI]: 1.46–13.27), while an inverse association was observed between no aggravation by routine activity and actual disability (OR: 0.32, 95% CI: 0.12–0.88). Multivariate analyses showed that ORs for headache impact were increased in those with higher headache frequency (OR: 2.54, 95% CI: 1.47–4.39 for 1–14 days/month; OR: 23.83, 95% CI: 5.46–104.03 for ≥ 15 days/month), longer headache time duration (OR: 1.84, 95% CI: 1.04–3.25 for ≥ 1 and < 4 hours; OR: 2.44 95% CI: 1.17–5.11 for ≥ 4 hours), and phonophobia (OR: 1.73, 95% CI: 1.02–2.95), whereas decreased in those with no aggravation by routine activity (OR: 0.32, 95% CI: 0.12–0.88). CONCLUSIONS: Several headache characteristics were associated with actual disability and headache impact among TTH individuals. Our findings suggest that there needs to be consideration careful of troublesome headache characteristics for TTH individuals suffering from disability and impact.