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The following is a summary of “Multicenter Validation of the Ocular Myasthenia Gravis Rating Scale Questionnaire,” published in the December 2024 issue of Neurology by Wong et al.
Researchers conducted a prospective study to validate the Ocular myasthenia gravis Rating Scale Questionnaire (OMGRate-q) as a patient-reported outcome measure (PROM) for individuals living with OMG.
The study involved 134 individuals with OMG (January 2022–October 2023) from 3 medical centers, 10-item OMGRate-q were completed. The response data were analyzed using exploratory factor analysis, followed by Andrich rating scale model fitting. Misfitting items were removed, and the model was refitted. Latent scores (theta) were estimated, test-retest reliability was assessed, and correlations with other myasthenia gravis PROMs were measured.
The results showed that 45 individuals (33.6%) were women, 99 (73.9%) were White, and the median age was 64.6 years (IQR, 52.6–73.9 years). A ptosis item showed significant deviation (P<0.001) and was treated separately from diplopia items. After removing an item, no misfitting items remained. Theta estimation for the subscale diplopia ranged from −3.47 to 5.51, with a median of −0.53 (IQR, −2.33 to 0.72). Test-retest reliability was high for the diplopia subscale (intraclass correlation coefficient = 0.95 [95%CI, 0.90–0.98]) and good for the ptosis item (weighted κ=0.56). No significant differences were found between sites (diplopia P=0.44; ptosis P=0.32). The OMGRate-q showed moderate to high correlations with the Myasthenia Gravis QoL 15 questionnaire (diplopia: r = 0.68, P<0.001; ptosis: r = 0.48, P<0.001) and the Myasthenia Gravis Impairment Index (diplopia: r = 0.76, P<0.001; ptosis: r = 0.77, P<0.001). Most participants (96.2%) found the questionnaire acceptable in length, and the mean completion time was 80.7 seconds (±45.2).
They concluded that the OMGRate-q was a valid and reliable disease-specific PROM for individuals living with OMG that can support patient-centered care and research.
Source: neurology.org/doi/10.1212/WNL.0000000000210150
