Test-retest reliability, minimal detectable change and convergent validity of the performance-based balance scale (PBS) in community-living older adults

Abstract

Balance assessment is critical to identify balance impairments in older adults and initiate balance improvement strategies to reduce fall risk. Current clinical balance tests have limitations including lengthy administration time, ceiling effects and lack of comprehensiveness. The Performance-based Balance Scale (PBS) is a recently developed comprehensive clinical balance test appropriate for use with Community-Living Older Adults (CLOAs). The PBS is uniquely designed in a non-fixed text format that eliminates the need to complete the entire test to determine the score. The purposes of this study were to examine the time to administer, test-retest reliability, minimal detectable change (MDC), and convergent validity of the PBS with CLOAs. Thirty-one CLOAs (3 men; 28 women; mean age = 69 yrs; 60–96 yrs) volunteered to participant in this study. Each participant was tested twice, 7 to 14 days apart, using the PBS. Test-retest reliability was determined using the intraclass correlation coefficient (ICC [2.1]). Minimal detectable change (MDC) and convergent validity were calculated. Time to administer of the PBS was 15 to 20 minutes. The PBS total score showed excellent test-retest reliability with ICC (2.1) = .97. The SEM for the PBS was 0.95, MDC 90% , was 2.2 and MDC 95% was 2.6. The convergent validity with the Short Physical Performance Battery was r = .71. The PBS is a feasible, valid, and reliable balance test to assess balance ability among CLOAs. Minimal detectable change scores at the 90% and 95% confidence interval can be used to assess over time change in balance ability.