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Objective: The purpose of this study was to assess psychometric properties of the six-item Headache Impact Text (HIT-6™) across episodic and chronic migraine.Methods: Using a migraine screener and number of headache days per month (HDPM), participants from the National Survey of Headache Impact (NSHI) study and the HIT-6 validation study (HIT6-V) were selected for this study. Eligible participants were categorized into three groups: chronic migraine (CM: ≥ 15 HDPM); episodic migraine (EM: < 15 HDPM); non-migraine headaches. Reliability and validity of the HIT-6 were evaluated.Results: A total of 2,049 survey participants met the inclusion/exclusion criteria for this study. Participants were identified as 6.4% CM; 42.1% EM; 51.5% non-migraine, with respective mean HIT-6 scores: 62.5 ± 7.8; 60.2 ± 6.8; and 49.1 ± 8.7. High reliability was demonstrated with internal consistency (time1/time2) of 0.83/0.87 in NSHI, and 0.82/0.92 in HIT6-V. Intra-class correlation for test-retest reliability was very good at 0.77. HIT-6 scores correlated significantly (p < .0001) with total Migraine Disability Assessment Scale scores (r = 0.56), headache pain severity (r = 0.46), and HDPM (r = 0.29). Discriminant validity analysis showed significantly different HIT-6 scores (F = 488.02, p < .0001) across the groups.Conclusion: Results from these analyses confirm that the HIT-6 is a reliable and valid tool for discriminating headache impact across episodic and chronic migraine.

The MSQ is a reliable and valid questionnaire in the CM population that can differentiate the functional impact between CM and EM. The MSQ can assist researchers in evaluating treatment effectiveness by obtaining input directly from the patients on multidimensional aspects other than frequency of headache days.

BackgroundThe Headache Impact Test (HIT)-6 was developed and has been validated in patients with various types of headache. The objective of this study was to report the psychometric properties of the HIT-6 among patients with chronic migraine.MethodsData came from two international, multicenter, randomized, double-blind, placebo-controlled clinical trials of chronic migraine patients (N = 1,384) undergoing prophylaxis therapy. Confirmatory factor analysis and differential item functioning (DIF) analysis were used to test the latent structure and cross-cultural comparability of the HIT-6. Reliability, construct validity, and responsiveness were assessed. Two sets of criterion groups were used: (1) 28-day headache frequency: <10, 10–14, and ≥15 days; (2) sample quartiles of the total cumulative hours of headache: <140, 140 to <280, 280 to <420, and ≥420 hours. Two sets of responsiveness categories were defined as reduction of <30%, 30% to <50%, or ≥50% in (1) number of headache days and (2) cumulative hours of headache.ResultsMeasurement invariance tests supported the stability of the HIT-6 latent structure across studies. DIF analysis supported cross-cultural comparability. Good reliability was observed across studies (Cronbach’s α: 0.75–0.92; intraclass correlation coefficient: 0.76–0.80). HIT-6 scores correlated strongly (−0.86 to −0.59) with scores of the Migraine-Specific Quality-of-Life Questionnaire. Analysis of variance indicated that HIT-6 scores discriminated across both types of criterion groups (P<0.001), across studies and time points. HIT-6 change scores were significantly higher in magnitude in groups experiencing greater improvement (P<0.001).ConclusionAll measurement properties were consistently verified across the two studies, supporting the validity of the HIT-6 among chronic migraine patients.Trial registrationNCT00156910 and NCT00168428 on www.ClinicalTrials.gov.

Objective The Migraine-Specific Quality of Life Questionnaire version 2.1 (MSQ) has been shown to have good psychometric performance in measuring headache impact in migraine patients, but its properties specifically in chronic migraine (CM) patients are unknown. The objective of this study was to evaluate the psychometric properties of the MSQ in a group of CM patients undergoing prophylactic treatment. Methods Measurement properties of the MSQ were examined using two international, multicenter, randomized clinical trials evaluating onabotulinumtoxinA as headache prophylaxis in CM patients (N = 1,376). Confirmatory factor analysis (CFA) was used to test the latent structure of the MSQ in CM patients. The reliability, convergent and discriminant validity, and responsiveness of the MSQ were assessed. Results CFA confirmed the currently proposed three-factor MSQ latent structure across the two studies. Good reliability was observed for all three MSQ scales, across studies and time points. MSQ scale scores strongly correlated with the scores of the Headache Impact Test-6 (HIT-6). Analysis of knowngroups validity indicated that MSQ scale scores discriminated between groups of patients differing in their 28-day headache frequency were as follows\10, 10-14, and C15 days, and the sample-derived quartiles of the total cumulative hours of headache were as follows \140, 140 to \280, 280 to \420, and C420 h (p \ 0.0001), across both studies and time points. MSQ change scores were higher in magnitude in groups experiencing greater decline in headache frequency (p \ 0.001). Conclusion The MSQ is a psychometrically valid tool that can be used to reliably measure the impact of migraine among CM patients.