Test–retest reliability and limits of agreement of the Six-Spot Step Test in people with Parkinson’s disease

Abstract

completed again. The agreement was estimated by Bland-Altman statistics with 95% limits of agreement, and reliability was estimated by the intraclass correlation coefficient. Results: Subjects had a mean (SD) age of 67.8 (6.8) years, a median (range) Hoehn and Yahr score of 2.5 (1-4) and a mean (SD) Six-Spot Step Test score of 8.1 (1.8), 7.6 (1.7) and 7.6 (1.6) seconds on test occasions 1 to 3. An agreement for within-day and day-today of ±1.8 (±23.7%) and ±2.2 (±26.7%) seconds was found, respectively. The reliability was 0.81 and 0.76 within-day and day-today , respectively. A small learning effect was observed (P < 0.05) between the first and second Six-Spot Step Test, but there was no learning between the second and third occasions. Conclusion: The Six-Spot Step Test has an acceptable within-day and day-today agreement and reliability in mild to moderately disabled people with Parkinson's disease. A change of 2.2 seconds can be regarded as a true change. To minimize learning effects, test trials of the Six-Spot Step Test are recommended before use.

A study of the validity of the Six-Spot Step Test in ambulatory people with Parkinson’s disease

“…The Six-Spot Step Test shows promising concurrent validity to other recommended clinical tests for encompassing balance capacity and functional mobility making it a reasonable and easily administered alternative to existing assessment scales and clinical tests. Furthermore, using the Six-Spot Step Test in clinical practice, one should expect a reliable assessment tool with an absolute measurement error of approximately two seconds or 25%, 3 as is also reported for related outcomes. 25…”

“…The Six-Spot Step Test was performed as described by Nieuwenhuis et al 4 (see Supplemental Figure 1), and it has been described in detail in a previous paper from our research group. 3 Importantly, before the start, all participants were verbally instructed and shown by the examiner how to perform the test. Hereafter, all participants completed one Six-Spot Step Test to avoid a potential learning effect between trials as has previously been shown to exist.…”

“…Hereafter, all participants completed one Six-Spot Step Test to avoid a potential learning effect between trials as has previously been shown to exist. 1,3 The Six-Spot Step Test consisted of four valid runs including two runs for each leg, starting with two runs for the dominant leg. A mean time of these four runs was calculated and served as the test result.…”

“…The Six-Spot Step Test is a recently developed test which combines the ability of the participant to maintain balance while challenging stability during walking in a single test. [1][2][3] Furthermore, the test will challenge strategies of planning movement including initiating and ending movements; it requires high limb dexterity and postural stability in one-leg stance. Finally, it taxes motor dual tasking and cognitive capacity.…”

“…Time since diagnosis (years, median (Q1-Q3)) 5(3)(4)(5)(6)(7)(8) The Six-Spot Step Test (seconds, median (Q1-Q3)) 7.9 (6.5-9.2) The Timed "Up and Go" test (seconds, median (Q1-Q3)) 7.0 (5.6-7.9) Mini-BESTest score (0-28) (median (Q1-Q3))22.5 (19.8-25.0) Subdivision Anticipatory score (0-6) (median (Q1-Q3)) 5 (4-6) Subdivision Reactive postural control score (0-6) (median (Q1-Q3)) 4 (3-5) Subdivision Sensory orientation score (0-6) (median (Q1-Q3)) 6 (5-6) Subdivision Dynamic Gait score (0-10) (median (Q1-Q3)) 8 (7-9) Postural sway, mm 2 (median (Q1-Q3)) 27.9 (15.0-53.5) Postural sway, mm/s (median (Q1-Q3)) 22.5 (14.6-39.8) Q1: first quartile; Q3: third quartile; Mini-BESTest: mini-Balance Evaluation Systems Test; postural sway (mm 2 ): the 95% confidence ellipse sway area; postural sway (mm/s): the median sway velocity.…”