An Anglo-Saxon consortium studied the psychometric properties of the IBMFRS (Inclusion Body Myositis Functional Rating Scale), the reference scale used in patients with inclusion myositis (IBM):
- to this end, the investigators retrospectively analysed the IBMFRS data accumulated during a multicentre clinical trial involving 150 patients with IBM, over a total period of 20 months,
- all the validity parameters of the scale were examined with a fine-tooth comb,
- the scale was found to be entirely appropriate, easy to administer, reliable and capable of capturing change,
- according to the authors, a loss of 2 points represents the threshold of significance for a real deterioration.
