High inter-rater reliability in analyzing results of decomposition-based quantitative electromyography in subjects with or without neuromuscular disorder

Decomposition-based quantitative electromyography (DQEMG) comprises a group of methods used to obtain information related to the health of the neuromuscular system. Although primarily objective, aspects of the data analysis protocol include operator decisions that may impact its reliability and reduce the applicability of the technique among multiple users. Thus, the objective of this study was to establish the inter-rater reliability of the protocol used for DQEMG analysis among five raters. Seventy data files previously obtained using DQEMG from healthy control subjects and patients with disorders of the neuromuscular system were analyzed by four novice and one experienced rater. Values obtained from this analysis were then evaluated for reliability within the novice raters and in contrast to the results of the experienced rater to examine the influence of the level of rater experience on the results obtained. The majority of the parameters associated with the number of motor unit potentials and their physiological characteristics were found to be reliable among all raters, with moderate-high ICC values observed for both the biceps brachii and first dorsal interosseous muscles. The data suggest that the level of rater experience does not greatly influence the results obtained and that the analysis can be reliably performed by a rater who is given suitable instruction. These findings are important particularly given the potential use of DQEMG as an outcome measure in multi-center studies. (C) 2010 Elsevier B.V. All rights reserved.