Minimal important difference of the Migraine Disability Assessment (MIDAS): Longitudinal data from the DMKG Headache...

Area of Science:

• Neurology
• Clinical Research
• Patient-Reported Outcomes

Background:

• The Migraine Disability Assessment (MIDAS) is a widely utilized tool for assessing migraine-related disability.
• Limited data exist on the minimal important difference (MID) for MIDAS scores, hindering interpretation of patient-perceived changes.
• The German Migraine and Headache Society (DMKG) Headache Registry provides a valuable dataset for this research.

Purpose of the Study:

• To determine the minimal important difference (MID) of the MIDAS score in a tertiary headache care population.
• To establish thresholds for clinically meaningful improvement in MIDAS scores based on patient perception.
• To enhance the interpretability of MIDAS scores in clinical practice and research.

Main Methods:

• Utilized data from the DMKG Headache Registry (DRKS 00021081).
• Employed the Patient Global Impression of Change (PGIC) as an anchor to define meaningful improvement.
• Applied average change and receiver operating characteristic (ROC) curve methods to calculate the MID for MIDAS scores.

Main Results:

• Included 1218 adult migraine patients (40.2 ± 12.8 years, 85.6% female).
• For patients with baseline MIDAS >20 (grade IV), the MID was estimated between -29.4% and -33.2% using PGIC "somewhat improved" as the anchor.
• For patients with baseline MIDAS 6-20 (grades II-III), the MID was between -3.5 and -4.5 points using PGIC "much improved" as the anchor.

Conclusions:

• The minimal important difference (MID) for MIDAS was estimated at approximately -30% for patients with a baseline MIDAS >20.
• For patients with a baseline MIDAS of 6-20, the MID was estimated at -4 points.
• These findings provide crucial benchmarks for interpreting MIDAS score changes in clinical settings.