Reliability, validity, and responsiveness of the Arabic version of HIT‐6 questionnaire in patients with migraine indicated for preventive therapy: A multi‐center study

Abstract

BackgroundThe Headache Impact Test (HIT‐6) is an important patient‐reported outcome measure (PROM) in migraine prevention trials.ObjectivesThis study aimed to (i) assess the reliability and validity of the Arabic version of HIT‐6 in Arabic‐speaking patients experiencing migraine, and (ii) evaluate the responsiveness of HIT‐6 following migraine preventive therapy.MethodsIn this prospective study, patients with migraine (n = 145) were requested to fill out a headache diary, the Arabic version of HIT‐6, and Migraine Disability Assessment Scale (MIDAS) at two time points (baseline and 3 months after initiation of prophylactic treatment). Some respondents (n = 73) were requested to fill out HIT‐6 again 1 week from the baseline for test–retest reliability. The intensity of migraine headache attacks was evaluated using the Visual Analogue Scale (VAS). An anchor‐based method was used to establish the minimal important change (MIC) value and responsiveness of HIT‐6.ResultsThe total scores of HIT‐6 were significantly correlated to a fair degree with MIDAS (r = 0.41), as well as VAS (r = 0.53), and monthly migraine days (r = 0.38) at the baseline while at the follow‐up (after 3 months), the correlations were of moderate degree with MIDAS scores (r = 0.62) and monthly migraine days (r = 0.60; convergent validity). Reliability estimates of the Arabic HIT‐6 were excellent (Cronbach's α = 0.91 at baseline and 0.89 at follow‐up). The average measure interclass correlation coefficient (ICC) value for the test–retest reliability was 0.96 (95% confidence interval = 0.94–0.98, p < 0.001). The HIT‐6 total score is sensitive to change, being significantly reduced after prophylactic treatment compared to before (effect size = 1.5, standardized response mean = 1.3). A reduction from baseline of 4.5 on HIT‐6 showed the highest responsiveness to predict improvement with an area under the curve equal to 0.66, sensitivity of 80%, specificity of 45%, and significance at 0.021. Changes in the HIT‐6 total score were positively correlated with changes in monthly migraine days (r = 0.40) and VAS scores (r = 0.69) but not with changes in the score of MIDAS (r = 0.07).ConclusionThe Arabic version of HIT‐6 is valid, reliable, and sensitive to detect clinical changes following migraine prophylactic treatment with a MIC of 4.5 points.