separated their study groups into two levels of cognitive impairment and published separate MDC scores for the groups (with MDC for the more cognitively impaired groups being greater than for the less cognitively impaired groups). The values listed in the table are for entire study populations. The table represents some of the most commonly used outcome measures with individuals who have dementia. Tests may need to be slightly modified to facilitate optimal performance. For example, timed up-and-go (TUG) adaptations might include beginning to time the activity when the individual’s bottom leaves the chair (rather than upon the “go” command) to allow for delayed response time and using a cone on the floor (in lieu of a tape mark) to signal turning and cueing during the test (e.g., “walk around that cone,” “sit in that chair”). Berg Balance Scale items may need constant coaching to incentivize optimal performance. It is important to be consistent from one testing session to another in terms of the testing environment, client interaction, and cueing. McGough et al. (2017) performed a review of physical performance outcome measures used with older adults with AD and other dementias and based upon the most frequently used measures recommended the use of: 6-minute walk test, TUG, repeated chair stands, short distance gait speed, Berg Balance Scale, and isometric strength measures. Fox, Henwood, Keogh, and Neville (2016) studied the psychometric viability of measures with this population and emphasized the level of research evidence in supporting their validity and reliability is lacking. This is an area that will continue to be studied.
comparing group performance results in a research study) but may not necessarily be sound for repeated measurement of one person’s performance over time. To follow one individual over time, the therapist should be assured that the measurement error and the expected variability of scores (i.e., any typical variation in performance from one test administration to the next) has been accounted for; this is referred to as absolute reliability of the outcome measure. One way to assess absolute reliability is with minimal detectable change (MDC) scores. The MDC value represents a “true” change in performance (i.e., change that is greater than the expected variability of performance and measurement error). MDC90 indicates with a 90% degree of confidence that a change in score greater than the MDC value represents a “true” change in performance (i.e., a “significant” improvement or decline in performance). One emerging theme is that absolute reliability (variability of individual performance) increases as the level of cognitive impairment increases (Blankevoort, van Heuvelen, & Scherder, 2013; Ries, Echternach, Nof, & Blodgett, 2009). Outcome measures that have been used for individuals with AD or dementia for which there are established MDC scores are listed in Table 7 (Blankevoort et al., 2013; Conradsson et al., 2007; Hesseberg, Bentzen, & Bergland, 2015; Muir-Hunter, Graham, & Montero Odasso, 2015; Ries et al., 2009; Suttanon, Hill, Dodd, & Said, 2011; Wittwer, Webster, Andrews, & Menz, 2008). Mean MMSE values are listed to describe the level of cognitive impairment of subjects in these study groups. Ries and colleagues (2009) and Blankevoort and colleagues (2013) Table 7: MDC Scores for Specific Outcome Measures Outcome Measure
MDC Values for Individuals With AD or Dementia (Reference Article)
Mean MMSE Score for Subject Population (Standard Deviation)
Timed Up-and-Go (TUG) Mobility assessment of the time it takes to rise from a chair, walk 3 meters, turn, and walk back to the chair, and sit down (measured in seconds)
MDC 90 = 4.09 seconds (Ries et al., 2009) MDC 95 = 5.88 seconds (Blankevoort et al., 2013)
13.1 (8.2)
19.2 (4.4)
MDC 95 = 2.42 seconds (Suttanon, Hill, Dodd, & Said, 2011)
21.4 (5.0)
MDC 95 = 3.44 seconds (Muir-Hunter et al., 2015) MDC 90 = 6.4 points (Conradsson et al., 2007) MDC 95 = 7.7 points (Conradsson et al., 2007) MDC 95 = 16.7 points (Muir-Hunter et al., 2015) MDC 90 = 33.5 meters (Ries et al., 2009) MDC 90 = 37.1 meters (Hesseberg et al., 2015) MDC 95 = 0.27 meters/second (Blankevoort et al., 2013) MDC 90 = 0.09 meters/second (Ries et al., 2009)
20.0 (5.5)
Berg Balance Test 14-item balance test with transitional movements, variable base of support, and functional standing tasks (4-point scale per item for max score of 56)
17.5 (6.3)
17.5 (6.3)
20.0 (5.5)
Six-Minute Walk Test Functional assessment of distance walked in 6 minutes (measured in meters)
13.1 (8.2)
24.3 (4.0)
Gait Speed (6-Meter Walk) Steady state speed of gait using stopwatch for 6-meter course (measured in meters/second) Gait Speed (GAITRite ® Walkway) Steady state speed of gait using computerized, sensored walkway (measured in meters/second)
19.2 (4.4)
13.1 (8.2)
MDC 95 = 0.11 meters/second (Wittwer, Andrews, Webster, & Menz, 2008)
22.0 (3.5)
Sit-to-Stand (5 times) Mobility/functional assessment of time required for five sit-to-stand repetitions (measured in seconds)
MDC 95 = 2.73 seconds (Suttanon et al., 2011)
21.4 (5.0)
EliteLearning.com/Physical-Therapy
Page 32
Powered by FlippingBook