Patient-acceptable symptom states in myasthenia gravis
- 22 September 2020
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Neurology
- Vol. 95 (12), e1617-e1628
- https://doi.org/10.1212/wnl.0000000000010574
Abstract
Objectives To estimate patient-acceptable symptom state (PASS) cut points for myasthenia gravis (MG) health scales. Methods We conducted an electronic survey that included the Myasthenia Gravis Impairment Index (MGII), EuroQol 5-Dimension (EQ5D), and a simple PASS question. PASS-anchored thresholds were estimated for the MGII questionnaire through receiver operating characteristic curves. We used the MGII PASS cut point in a validation cohort of 257 patients to estimate PASS thresholds for other clinically relevant health scales such as the Quantitative Myasthenia Gravis Scale (QMGS), Myasthenia Gravis Activities of Daily Living (MG-ADL), Myasthenia Gravis Composite (MGC), and Myasthenia Quality of Life (MG-QoL15). Results One hundred twenty-four of ≈250 invited patients answered the electronic survey (49% response rate), and 80 considered their current symptom state acceptable (PASS-positive). They had lower MGII scores than PASS-negative patients (7.76 ± 9.37 vs 25.0 ± 13.7, p < 0.0001) and better EQ5D scores (0.86 ± 0.17 vs 0.69 ± 0.18, p < 0.0001). The MGII questionnaire threshold for PASS was ≤10 points. With the use of this threshold in an independent dataset of 257 patients, all patients in remission or minimal manifestation status were PASS-positive. In addition, some patients in Classes I, II, and IIIA also achieved PASS status. PASS thresholds for the QMGS, MG-ADL, MGC, and MG-QoL15 were ≤7, 2, 3, and 8 points, respectively. Conclusions We have estimated thresholds for commonly used myasthenia health scales reflecting patient-acceptable states in patients with MG. These thresholds indicate a global state of well being, rather than a change in scores, or being better. Therefore, PASS thresholds can be used as secondary endpoints for myasthenia research.Keywords
This publication has 37 references indexed in Scilit:
- Minimum clinically important improvement and patient acceptable symptom state in pain and function in rheumatoid arthritis, ankylosing spondylitis, chronic back pain, hand osteoarthritis, and hip and knee osteoarthritis: Results from a prospective multinational studyArthritis Care & Research, 2012
- The MG‐QOL15 for following the health‐related quality of life of patients with myasthenia gravisMuscle & Nerve, 2010
- The MG CompositeNeurology, 2010
- Autoimmune myasthenia gravis: emerging clinical and biological heterogeneityThe Lancet Neurology, 2009
- Quality criteria were proposed for measurement properties of health status questionnairesJournal of Clinical Epidemiology, 2007
- Feeling good rather than feeling better matters more to patientsArthritis Care & Research, 2006
- Myasthenia gravisNeurology, 2000
- Reliability Testing of the Quantitative Myasthenia Gravis ScoreaAnnals of the New York Academy of Sciences, 1998
- EuroQol: the current state of playHealth Policy, 1996
- The meaning and use of the area under a receiver operating characteristic (ROC) curve.Radiology, 1982