The Myasthenia Gravis-Health Index (MG-HI): Development and Validation of a Disease-Specific, Patient-Reported Outcome Measure

Topic:

Translational Research

Poster Number: 212 M

Author(s):

Charlotte Engebrecht, BS, University of Rochester Center for Health + Technology, Spencer Rosero, BS, University of Rochester Center for Health + Technology, Jennifer Weinstein, MS, University of Rochester Center for Health + Technology, Christina Shupe, MPH, University of Rochester Center for Health + Technology, Charlotte Irwin, BS, University of Rochester Center for Health + Technology, Preshetha Kanagaiah, B.S., Center for Health + Technology, University of Rochester Medical Center, Alicia Brocht, MS, University of Rochester Center for Health + Technology, John Heatwole, Cornell University, Olimpia Carbunar, MD, University of Miami, Michael Benatar, University of Miami, Chad Heatwole, MD, University of Rochester

Background
In order to facilitate therapeutic advancement in myasthenia gravis (MG), there is a need to develop and validate regulatory-grade, multifactorial, disease-specific patient-reported outcome (PRO) measures. When well designed, PROs can be used to detect clinically-relevant changes in symptoms that have been identified as the most prevalent and impactful to the disease population.

Objectives
To develop and validate a patient-reported outcome measure following U.S Food and Drug Administration (FDA) guidelines to support drug-labeling claims in MG.

Results
Fifteen individuals with ocular or generalized MG participated in qualitative interviews and 222 individuals completed an online cross-sectional survey to determine which symptoms are most appropriate to include in the MG-HI. Beta testing of the MG-HI was conducted with 17 individuals with MG who found the MG-HI to be comprehensive, easy to use, and relevant to their symptoms. Twenty individuals with MG participated in test-retest reliability which demonstrated the MG-HI’s reliability (ICC = 0.854) and strong internal consistency of the MG-HI Full Form (Cronbach’s alpha = 0.977). Known groups analysis demonstrated the MG-HI’s ability to detect differences in disease burden by type of MG, swallowing function, speech function, prednisone dosage, ambulation status, disability status, and level of disability. The resulting MG-HI consists of 14 subscales, each of which measure patient perspective on the following symptomatic domains: 1) mobility & ambulation; 2) back, chest, & abdominal strength; 3) hand & finger function; 4) shoulder & arm function; 5) emotional health; 6) social health; 7) breathing function; 8) activity participation; 9) fatigue; 10) pain; 11) swallowing function; 12) communication; 13) vision; and 14) sleep & daytime sleepiness.

Conclusion
The MG-HI is a validated and reliable PRO that captures the multifaceted impact of MG from the patient’s perspective, while providing researchers and clinicians with a robust tool to quantify disease burden in response to therapeutic intervention.