Standards of Measurements in Myasthenia Gravis

Abstract

In 1997, the Medical Scientific Advisory Board of the Myasthenia Gravis Foundation of America formed a Task Force to develop classification and outcome measures for myasthenia gravis (MG). The goal of the Task Force was to achieve uniformity in recording and reporting clinical trials and outcomes research. The Task Force met frequently over a three-year period, obtained input from national and international experts, and produced a consensus document on recommendations for MG clinical research standards. In this article, the essential elements of the Task Force's recommendations will be summarized. In addition, several other MG measurement tools that are in various stages of development are mentioned.

Long-term benefit of rituximab in MuSK autoantibody myasthenia gravis patients: Table 1

“…Patients were defined as refractory when they: (1) could not lower their immunotherapy without clinical relapse, (2) were not clinically controlled on their immunotherapy regimen or (3) had intolerable side effects from treatment. We examined immunotherapy regimens, time to taper off these therapies, clinical exams, MG Foundation of America Clinical Classification scores, Post-Intervention Status (PIS),8 duration since first and last rituximab cycle and qualitative MuSK antibody status (table 1). MuSK antibody testing was performed at Athena Diagnostics (Worcester, Massachusetts, USA).…”

History of outcome measures for myasthenia gravis

“…[52][53][54] A slightly modified MG numerical scale was used as one of the primary outcome measures in a trial that demonstrated the efficacy of cyclosporine in MG. 55,56 This scale was modified once more in the late 1990s, notably by replacing subjective assessments of speech and swallowing taken from the history with more objective tests of counting aloud to 50 and swallowing 4 ounces of water (Supporting Table 3). 57 The cyclosporine trials 55,56 and QMG interrater reliability testing [57][58][59] suggested that a three-point change in QMG score should be considered significant. The MSAB of the MGFA formed a task force in May 1997 to address the need for universally accepted classifications, grading systems, and methods of analysis.…”

Myasthenia and related disorders of the neuromuscular junction

“…This is most likely due to improved ventilatory care and increased availability of immunomodulatory treatments 3 15. Assessment of outcome has been helped by the establishment of a task force by the Myasthenia Gravis Foundation of America in 1997, which led to recommendations for clinical research standards, including uniformity in the reporting of clinical trials 16 17…”