extended · article · 2011

Modifying the Medical Research Council grading system through Rasch analyses

Els Karla Vanhoutte; Catharina G. Faber; Sonja I. van Nes; Bart C. Jacobs; Pieter A. van Doorn; Rinske van Koningsveld; David Reid Cornblath; Anneke J. van der Kooi; Elisabeth A. Cats; Leonard Hendrik van den Berg; Nicolette C. Notermans; Willem Lodewijk van der Pol; Mieke Catharina Elisabeth Hermans; Nadine A. M. E. van der Beek; Kenneth C. Gorson; M. Eurelings; Jeroen Engelsman; Hendrik Boot; R.J. Meijer; Giuseppe Lauria; Alan Tennant; Ingemar S.J. Merkies

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 cate...