Reference Values for the Headache Impact Test-6 Questionnaire

Objective: To determine reference values for the Headache Impact Test-6 (HIT-6) in a young, physically active cohort and to examine the influence of sex, concussion history, headache history, and competitive sport level on HIT-6 scores. Design: Cross-sectional. Setting: United States Service Academy. Participants: United States Service Academy cadets (N=2678) completed an HIT-6 questionnaire as part of their annual concussion baseline assessment. Cadets with a recent concussion were excluded from baseline testing. Interventions: Not applicable. Main Outcome Measures: Reference values were calculated and stratified by sex, concussion history, headache history, and competitive sport level. Mann-Whitney U and Kruskal-Wallis tests were used to examine the effect of sex, concussion history, headache history, and competitive sport level on HIT-6 scores (P<.05). Results: Of the 3599 cadets baselined, 2687 cadets (23% female) agreed to participate in the study and completed the HIT-6. Female participants reported significantly worse HIT-6 scores compared with male participants both with (P<.001) and without (P<.001) a concussion history. In both sexes, participants with a headache history reported worse scores than those with no headache/concussion history and a concussion history (all P<.005). Female cadets who participated in intramural athletics reported worse HIT-6 scores at baseline than female intercollegiate athletes (P=.003). Conclusions: This is the first study to stratify HIT-6 data by sex, concussion history, headache history, and sport level in a collegiate population at risk for concussions. Sex and headache history appear to influence HIT-6 scores and should be given special consideration when interpreting health-related quality of life deficits due to headache.