Quantitative functional measures in MS: what is a reliable change?

As a first step toward understanding which changes should be considered as meaningful, the authors assessed the reliability of quantitative functional tests on 5 consecutive days in 63 patients with MS, determining the range of measurement variability present when patients are clinically stable. Time to walk 25 feet (T25FW) and the 9-hole peg test (9HPT) varied by <20% of individual mean scores on repeated testing. Therefore, a 20% change on these tests can be considered to be the threshold that reliably indicates a true change in function for an individual.