Background: The literature contains few reports of the test-retest reliability of performance-based measures. The purpose of this study was to determine the test-retest reliability of a battery of seven timed, performance-based measures used to assess the functional limitations of frail, older adults.
Methods: One hundred and five frail, elderly subjects were twice administered a battery of timed tests approximately 2 weeks apart: 8-foot walk, get-up-and-go test, stair climb, single and repetitive standing from a chair, and single and repetitive 10-pound lifts with the upper limbs. Agreement between the mean times recorded for accomplishing each task at the two administrations was assessed.
Results: Intraclass correlation coefficients ranged from .25 for the single chair stand to .79 for the 8-foot walk. Only the time taken for the single 10-pound lift was significantly greater at the first administration as compared with the second.
Conclusions: Timed performance-based measures have a wide range of test-retest reliability. Performance-based protocols that reflect familiar tasks with discrete starting and ending points may achieve higher reliability than tasks that are unfamiliar to subjects or may have ambiguous elements in them.