TY - JOUR
T1 - Rasch-Built Overall Disability Scale for IgM-Associated Polyneuropathy With and Without Anti-MAG Antibodies
T2 - IgM-RODS
AU - Hamadeh, Tatiana
AU - van de Mortel, Johannes P.M.
AU - Hoeijmakers, Janneke G.J.
AU - Cornblath, David R.
AU - Vrancken, Alexander F.J.E.
AU - Faber, Catharina G.
AU - Notermans, Nicolette C.
AU - van Doormaal, Perry T.C.
AU - Merkies, Ingemar S.J.
AU - IMAGiNe Consortium
N1 - Publisher Copyright:
© 2025 Peripheral Nerve Society.
PY - 2025/9/1
Y1 - 2025/9/1
N2 - BACKGROUND AND AIM: IgM monoclonal gammopathy-associated polyneuropathy with(out) anti-myelin associated glycoprotein (±anti-MAG) is a rare immune-mediated disease that may cause severe limitations in daily activities and quality of life. The absence of a systematic comparison between patients with/without anti-MAG IgM polyneuropathy, no disease-specific functional metric, and lack of international consensus regarding assessment and treatment of these patients are factors obstructing future clinical trials. Therefore, it was decided to develop an interval Rasch-built activity/participation scale specifically for IgM polyneuropathy ±anti-MAG (IgM-RODS) and examine its clinimetric properties. METHODS: A pre-phase IgM-RODS questionnaire containing 146 activity/participation items, based on the WHO International Classification of Functioning, Disability and Health, was completed by participants (= 18 years) of the IMAGiNe observational registry that fulfilled international criteria for IgM-polyneuropathy ±anti-MAG. Data was subjected to Rasch analyses, and reliability/validity studies were performed as well. RESULTS: The pre-RODS data of 259 subjects (originating from 8 different countries) underwent quality assessment, and 244 remaining records were submitted to the Rasch model, evidencing the model's expectations. Based on requirements like exceeding fit residuals, misfit statistics, item bias, local dependency, and less face validity, we systematically removed items until the final 36-item IgM-RODS fulfilled all Rasch requirements and showed acceptable test-retest reliability, cross-cultural, construct and discriminant validity, and unidimensionality. Compared to the Inflammatory-RODS, the IgM-RODS showed lower standard errors across the metric, indicating greater sensitivity. INTERPRETATION: The 36-item IgM-RODS is a disease-specific interval measure suitable for detecting functional deficits in patients with IgM-polyneuropathy ±anti-MAG. Future studies are needed to determine its responsiveness.
AB - BACKGROUND AND AIM: IgM monoclonal gammopathy-associated polyneuropathy with(out) anti-myelin associated glycoprotein (±anti-MAG) is a rare immune-mediated disease that may cause severe limitations in daily activities and quality of life. The absence of a systematic comparison between patients with/without anti-MAG IgM polyneuropathy, no disease-specific functional metric, and lack of international consensus regarding assessment and treatment of these patients are factors obstructing future clinical trials. Therefore, it was decided to develop an interval Rasch-built activity/participation scale specifically for IgM polyneuropathy ±anti-MAG (IgM-RODS) and examine its clinimetric properties. METHODS: A pre-phase IgM-RODS questionnaire containing 146 activity/participation items, based on the WHO International Classification of Functioning, Disability and Health, was completed by participants (= 18 years) of the IMAGiNe observational registry that fulfilled international criteria for IgM-polyneuropathy ±anti-MAG. Data was subjected to Rasch analyses, and reliability/validity studies were performed as well. RESULTS: The pre-RODS data of 259 subjects (originating from 8 different countries) underwent quality assessment, and 244 remaining records were submitted to the Rasch model, evidencing the model's expectations. Based on requirements like exceeding fit residuals, misfit statistics, item bias, local dependency, and less face validity, we systematically removed items until the final 36-item IgM-RODS fulfilled all Rasch requirements and showed acceptable test-retest reliability, cross-cultural, construct and discriminant validity, and unidimensionality. Compared to the Inflammatory-RODS, the IgM-RODS showed lower standard errors across the metric, indicating greater sensitivity. INTERPRETATION: The 36-item IgM-RODS is a disease-specific interval measure suitable for detecting functional deficits in patients with IgM-polyneuropathy ±anti-MAG. Future studies are needed to determine its responsiveness.
KW - function Rasch-built metric
KW - IgM polyneuropathy
KW - IgM RODS
U2 - 10.1111/jns.70059
DO - 10.1111/jns.70059
M3 - Article
SN - 1085-9489
VL - 30
JO - Journal of the Peripheral Nervous System
JF - Journal of the Peripheral Nervous System
IS - 3
M1 - e70059
ER -