Reliability of grip strength, walking time and button test performed according to a standard protocol.

Excellent interobserver and intraobserver reliability (reproducibility) was seen for the grip strength, walking time and button test measures in 40 patients with rheumatoid arthritis (RA), when measurement was performed according to a standard protocol. Evidence of reliability, coupled with the observation that baseline measures predict longterm morbidity and mortality in individual patients, suggests that these measures might be more widely used in general rheumatologic care.