Minimal important differences in the Migraine-Specific Quality of Life Questionnaire (MSQ) version

Area of Science:

• Neurology
• Psychometrics
• Clinical Trials

Background:

• The Migraine-Specific Quality of Life Questionnaire version 2.1 (MSQ v2.1) is a key tool for assessing migraine impact.
• Establishing minimal important differences (MID) for the MSQ v2.1 is essential for interpreting clinical significance but has not been previously published.

Purpose of the Study:

• To propose and validate minimal important difference (MID) values for the Migraine-Specific Quality of Life Questionnaire version 2.1 (MSQ v2.1).
• To provide guidance for interpreting MSQ v2.1 scores in clinical trials and patient assessments.

Main Methods:

• Utilized data from two topiramate migraine prevention trials (n=916) and the QualityMetric National Headache Survey (n=1016).
• Employed both distribution-based and anchor-based MID techniques at both group and individual levels.
• Calculated MID values for Role Restrictive (RR), Role Preventive (RP), and Emotional Functioning (EF) domains of the MSQ v2.1.

Main Results:

• Group-level anchor-based MIDs ranged from 3.2 (RR) to 7.5 (EF).
• Individual-level distribution-based MIDs were 8.5 (RR), 9.2 (RP), and 12.0 (EF).
• Individual-level anchor-based MIDs ranged from 5.0 (RR/RP) to 10.6 (EF).

Conclusions:

• Recommended group-level MIDs for power analysis: 3.2 (RR), 4.6 (RP), 7.5 (EF).
• Suggested individual-level MIDs for responder analyses: 5 points for RR; 5.0-7.9 for RP; 8.0-10.6 for EF.
• Emphasized the need for sensitivity analyses for RP and EF individual-level MIDs due to potential error.