What is a clinically relevant change on the HIT-6 questionnaire? An estimation in a primary-care population of migraine patients. (January 2014)

• Record Type: Journal Article
• Authors: Smelt, Antonia FH; Assendelft, Willem JJ; Terwee, Caroline B; Ferrari, Michel D; Blom, Jeanet W
• Is Part Of: Cephalalgia. Volume 34:Number 1(2014)
• Page Start: 29
• Page End: 36
• Publication Date: 2014-01
• Subjects: Migraine -- Headache Impact Test (HIT-6) -- minimally important change -- minimally important difference -- outcome research; Headache -- Periodicals; 616.8491
• DOI: 10.1177/0333102413497599
• Languages: English
• ISSNs: 0333-1024

Abstract

Objective: To interpret questionnaire scores, clinicians and researchers need to know what change in score reflects a meaningful change in the condition of an individual patient, and what difference reflects a meaningful difference between groups. These values differ between different populations. We determined the within-person minimally important change (MIC) and the between-group minimally important difference (MID) of the Headache Impact Test-6 (HIT-6) questionnaire in a primary-care population of migraine patients. Methods: We included 490 patients who participated in a clinical trial on the treatment of migraine in primary care. We compared their change scores on the HIT-6 questionnaire between baseline and at three-months follow-up with the answers to two anchor questions according to the 'mean change approach' and the 'ROC curve approach'. Results: The within-person MIC was estimated to be between −2.5 points (mean change approach) and −6 points (ROC curve approach). The choice for the within-person MIC value depends on the consequences of false positives and false negatives in a particular setting. The between-group MID was estimated at −1.5 points. Conclusions: We determined the within-person MIC and between-group MID for the HIT-6 in a primary-care population of migraine patients. We recommend the use of these values for clinical care and for research.