Concurrent validity and minimum detectable change of Senior Fitness Test components: instrumented vs. manual assessment
Physical Therapy and Rehabilitation
The Senior Fitness Test is a reliable and valid battery of individual tests which collectively measure the strength, balance, and endurance necessary to perform activities of daily living. These tests require little equipment or cost to administer, and are commonly administered in both clinical and community settings. However, with recent and rapid advancements in technology, there is now frequent use of wearable sensors to assess and quantify mobility tasks. It was the primary aim of the
... t study to compare the relative and absolute test-retest reliability of body-worn sensors vs. manual assessment of Senior Fitness Test components. Methods: Participants (65 years and older) attended a single 2-hour test session at a university academic building, where they performed two blocks of 3 tests (30-Second Chair Stand, 8-Foot Up-and-Go, and 6-Minute Walk Test) with a 45 minute to one hour rest in between blocks. Ambulatory Parkinson's Disease Monitoring (APDM) Opal sensors and stopwatch methods simultaneously measured the intended outcomes for each test. Test-retest relative reliability for the fitness tests was assessed with intra-class correlation coefficients(ICC (2,1) ). The agreement between test and retest was assessed by calculating minimum detectable change, which reflects the smallest amount of absolute change from test to retest that can be considered real. Results: Participants included 17 females and 11 males (Age=70.6±5.4 years; Body Mass=70.6±15.3 kg; Height=1.66±0.08m). All manual 6-Minute Walk Test outcomes exhibited excellent test-retest reliability (ICC≥0.96). The same was true of APDM, except for turn duration (ICC>0.74) and the number of steps in turn (ICC>0.61). Test-retest reliability for the 30-Second Chair Stand and 8-Foot Up-and-Go were excellent for the manual method (ICC>0.83 and >0.88, respectively), but were poor for APDM (ICC>0.41 and >0.28, respectively). Minimum detectable change was similar between the APDM and manual methods for 6-Minute Walk Test cadence (6.8 vs. 6.6 steps/min, respectively) and gait speed (0.11 vs. 0.13 m/s, respectively). There were substantial differences between manual and APDM minimum detectable change for the 30-Second Chair Stand and 8-Foot Up-and-Go, with APDM requiring approximately twice as much change, compared with manual. Conclusions: Both the APDM system and manual methods reliably and validly assessed gait speed and cadence during the 6-Minute Walk Test, though it should be noted that APDM only successfully recorded and reported data for 2 out of every 3 participants. The manual method of assessing the 8-Foot Up-and-Go and 30-Second Chair Stand was more valid and reliable than the APDM method. Citation: Salvatore MD, Colacino AM, Hess ME, Todd SW and Saunders NW. Concurrent validity and minimum detectable change of Senior Fitness Test components: instrumented vs. manual assessment. Phys Ther Rehabil. 2017; 4:13. http://dx.