To evaluate the measurement properties of all three domains of the Migraine-Specific Quality of Life questionnaire version 2.1 (MSQ v2.1) electronic patient-reported outcome (ePRO) to assess the functional impact of migraine in patients with episodic or chronic migraine (CM); and identify meaningful within-patient change thresholds for the Role Function-Restrictive (RFR), Role Function-Preventive (RFP), and Emotional Function (EF) domains.
Data were drawn from three double-blind, placebo-controlled, and randomized Phase 3 clinical studies (episodic migraine [EM]: EVOLVE-1 and EVOLVE-2; CM: REGAIN). The psychometric properties of the MSQ v2.1 ePRO domains were demonstrated by evaluating reliability (internal consistency and test-retest), construct validity (convergent and known groups), and responsiveness. Meaningful within-patient change thresholds for domains were estimated using anchor-based approaches, supplemented by empirical cumulative distribution function curves and probability density function plots to enable interpretation of meaningful change over 3 months. The Patient Global Impression of Severity (PGI-S) and Patient Global Impression of Improvement served as anchors.
A total of 2,850 patients with either EM (EVOLVE-1: 851; EVOLVE-2: 909) or CM (REGAIN: 1,090) were included. The Cronbach’s alpha estimates of internal consistency exceeded the recommended threshold of ≥0.70 for all domains from the three studies, indicating adequate internal consistency. Test-retest reliability intraclass correlation coefficients were ≥0.80 for all domains across all three studies, demonstrating almost perfect agreement. Convergent validity was supported by moderate-to-strong correlation (r ≥ 0.30) between all domains of MSQ v2.1 ePRO and studied anchors (Migraine Disability Assessment Score and PGI-S scores) across all three studies. Known group validity was established between all domains and subgroups of patients stratified by baseline PGI-S scores and baseline number of monthly migraine headache days for all three studies. The 3-month meaningful within-patient change thresholds were the same for EM and CM for RFP: 20.00 and EF: 26.67; and for RFR: 25.71.
These findings demonstrate that all three domains of the MSQ v2.1 ePRO have sufficient reliability, validity, responsiveness, and appropriate interpretation standards. Our results suggest that MSQ v2.1 ePRO is a well-defined and reliable patient-reported outcome instrument that is suitable for use in clinical studies for evaluating the impact of migraine on patient functioning in episodic and CM.