Reliability and Validity of Turkish Version of Headache Impact Test (HIT-6) in Patients with Migraine

INTRODUCTION: The Headache Impact Test (HIT-6) is a self-report questionnaire designed to evaluate the impact of headache on quality of life. The aim of this study is to assess reliability and validity of Turkish version of HIT-6 questionnaire in patients with migraine. METHODS: A total of 114 patients with migraine were included in this multicenter, prospective, descriptive study conducted at two consecutive visits 4 weeks apart. Comprehensibility, patient-physician reliability, internal consistency, test-retest reliability and validity of the translated HIT-6 were analyzed. RESULTS: Patients identified that HIT-6 items were “well-understood” in both visit 1 (ranged from 88.6% to 95.7%) and visit 2 (ranged from 93.0% to 98.2%). A highly positive correlation (R=0.876, p<0.001) was noted between visit 1 scores related to self-administered and physician-administered HIT-6 scores. Internal consistency analyzed via Cronbach’s α values for visit 1 and visit 2 HIT-6 scores in all patients were 0.753 (acceptable) and 0.864 (excellent), respectively. HIT-6 scores of patients (64.13 (6.20) and 62.70 (7.04), at visits 1 and 2, respectively, p=0.07) showed a moderate test-re-test reliability (R=0.437, p=0.0004). The HIT-6 score positively correlated with visit 1 and visit 2 headache severity-Likert scale (R=0.451 and 0.478, respectively, p<0.001) and VAS (R=0.365 and 0.531, respectively p<0.001) scores, and with visit 2 headache days for a month (R=0.215, p=0.022). CONCLUSION: These results demonstrated that the Turkish translation is equivalent to English version of HIT-6 in terms of internal consistency and it has moderate test-retest reliability and validity as correlated with headache severity, VAS and headache days for a month.