TY - JOUR
T1 - Modifying the Medical Research Council grading system through Rasch analyses
AU - Vanhoutte, Els Karla
AU - Faber, Catharina Gerritdina
AU - van Nes, Sonja Ingrid
AU - Jacobs, Bart Casper
AU - van Doorn, Pieter Antoon
AU - van Koningsveld, Rinske
AU - Cornblath, David Reid
AU - van der Kooi, Anneke Jelly
AU - Cats, Elisabeth Aviva
AU - van den Berg, Leonard Hendrik
AU - Notermans, Nicolette Claudia
AU - van der Pol, Willem Lodewijk
AU - Hermans, Mieke Catharina Elisabeth
AU - van der Beek, Nadine Anna Maria Elisabeth
AU - Gorson, Kenneth Craig
AU - Eurelings, Marijke
AU - Engelsman, Jeroen
AU - Boot, Hendrik
AU - Meijer, Ronaldus Jacobus
AU - Lauria, Giuseppe
AU - Tennant, Alan
AU - Merkies, Ingemar Sergio José
AU - AUTHOR GROUP
AU - Barreira, A. A.
AU - Bennett, D.
AU - van den Bergh, P. Y. K.
AU - Bril, V.
AU - Devigili, G.
AU - Hadden, R. D.
AU - Hahn, A. F.
AU - Hartung, H.-P.
AU - Hughes, R. A. C.
AU - Illa, I.
AU - Katzberg, H.
AU - Léger, J.-M.
AU - Lewis, R. A.
AU - Lunn, M. P. T.
AU - Nascimento, O. J. M.
AU - Nobile-Orazio, E.
AU - Padua, L.
AU - Pouget, J.
AU - Reilly, M. M.
AU - van Schaik, I.
AU - Smith, B.
AU - de Visser, M.
AU - Walk, D.
PY - 2012/5
Y1 - 2012/5
N2 - The Medical Research Council grading system has served through decades for the evaluation of muscle strength and has been recognized as a cardinal feature of daily neurological, rehabilitation and general medicine examination of patients, despite being respectfully criticized due to the unequal width of its response options. No study has systematically examined, through modern psychometric approach, whether physicians are able to properly use the Medical Research Council grades. The objectives of this study were: (i) to investigate physicians' ability to discriminate among the Medical Research Council categories in patients with different neuromuscular disorders and with various degrees of weakness through thresholds examination using Rasch analysis as a modern psychometric method; (ii) to examine possible factors influencing physicians' ability to apply the Medical Research Council categories through differential item function analyses; and (iii) to examine whether the widely used Medical Research Council 12 muscles sum score in patients with Guillain-Barre syndrome and chronic inflammatory demyelinating polyradiculoneuropathy would meet Rasch model's expectations. A total of 1065 patients were included from nine cohorts with the following diseases: Guillain-Barre syndrome (n = 480); myotonic dystrophy type-1 (n = 169); chronic inflammatory demyelinating polyradiculoneuropathy (n = 139); limb-girdle muscular dystrophy (n = 105); multifocal motor neuropathy (n = 102); Pompe's disease (n = 62) and monoclonal gammopathy of undetermined related polyneuropathy (n = 8). Medical Research Council data of 72 muscles were collected. Rasch analyses were performed on Medical Research Council data for each cohort separately and after pooling data at the muscle level to increase category frequencies, and on the Medical Research Council sum score in patients with Guillain-Barre syndrome and chronic inflammatory demyelinating polyradiculoneuropathy. Disordered thresholds were demonstrated in 74-79% of the muscles examined, indicating physicians' inability to discriminate between most Medical Research Council categories. Factors such as physicians' experience or illness type did not influence these findings. Thresholds were restored after rescoring the Medical Research Council grades from six to four options (0, paralysis; 1, severe weakness; 2, slight weakness; 3, normal strength). The Medical Research Council sum score acceptably fulfilled Rasch model expectations after rescoring the response options and creating subsets to resolve local dependency and item bias on diagnosis. In conclusion, a modified, Rasch-built four response category Medical Research Council grading system is proposed, resolving clinicians' inability to differentiate among its original response categories and improving clinical applicability. A modified Medical Research Council sum score at the interval level is presented and is recommended for future studies in Guillain-Barre syndrome and chronic inflammatory demyelinating polyradiculoneuropathy
AB - The Medical Research Council grading system has served through decades for the evaluation of muscle strength and has been recognized as a cardinal feature of daily neurological, rehabilitation and general medicine examination of patients, despite being respectfully criticized due to the unequal width of its response options. No study has systematically examined, through modern psychometric approach, whether physicians are able to properly use the Medical Research Council grades. The objectives of this study were: (i) to investigate physicians' ability to discriminate among the Medical Research Council categories in patients with different neuromuscular disorders and with various degrees of weakness through thresholds examination using Rasch analysis as a modern psychometric method; (ii) to examine possible factors influencing physicians' ability to apply the Medical Research Council categories through differential item function analyses; and (iii) to examine whether the widely used Medical Research Council 12 muscles sum score in patients with Guillain-Barre syndrome and chronic inflammatory demyelinating polyradiculoneuropathy would meet Rasch model's expectations. A total of 1065 patients were included from nine cohorts with the following diseases: Guillain-Barre syndrome (n = 480); myotonic dystrophy type-1 (n = 169); chronic inflammatory demyelinating polyradiculoneuropathy (n = 139); limb-girdle muscular dystrophy (n = 105); multifocal motor neuropathy (n = 102); Pompe's disease (n = 62) and monoclonal gammopathy of undetermined related polyneuropathy (n = 8). Medical Research Council data of 72 muscles were collected. Rasch analyses were performed on Medical Research Council data for each cohort separately and after pooling data at the muscle level to increase category frequencies, and on the Medical Research Council sum score in patients with Guillain-Barre syndrome and chronic inflammatory demyelinating polyradiculoneuropathy. Disordered thresholds were demonstrated in 74-79% of the muscles examined, indicating physicians' inability to discriminate between most Medical Research Council categories. Factors such as physicians' experience or illness type did not influence these findings. Thresholds were restored after rescoring the Medical Research Council grades from six to four options (0, paralysis; 1, severe weakness; 2, slight weakness; 3, normal strength). The Medical Research Council sum score acceptably fulfilled Rasch model expectations after rescoring the response options and creating subsets to resolve local dependency and item bias on diagnosis. In conclusion, a modified, Rasch-built four response category Medical Research Council grading system is proposed, resolving clinicians' inability to differentiate among its original response categories and improving clinical applicability. A modified Medical Research Council sum score at the interval level is presented and is recommended for future studies in Guillain-Barre syndrome and chronic inflammatory demyelinating polyradiculoneuropathy
U2 - https://doi.org/10.1093/brain/awr318
DO - https://doi.org/10.1093/brain/awr318
M3 - Article
C2 - 22189568
SN - 0006-8950
VL - 135
SP - 1639
EP - 1649
JO - Brain
JF - Brain
IS - 5
ER -