Objectives: In order to improve the universal quality of the EMG examination, knowledge about the variation among physicians is needed.
Methods: The variation among physicians in diagnostic strategy or criteria for diagnosing was analysed from a multicentre database with 940 EMG examinations sampled by seven physicians from six laboratories in Europe.
Results: For the whole group of patients as well as for the subgroup of patients with polyneuropathy, variation among physicians in examination techniques, number of examined structures per patient and number of abnormal structures per patient required for a diagnosis was found. Some of the variation may be explained by use of different techniques, which showed differences in sensitivity, while some of the variation may be due to differences in diagnostic strategy and criteria for diagnosing.
Conclusions: The study indicates a need for development and revision of international guidelines for EMG practice although implementation of standards requires caution.