Abstract
Background and Purpose: It is very important to analyze and estimate physical limitations in older people to prevent falls and further physical decline. Walking speed can be used as an outcome measure for evaluating a physical exercise program, but to do so, relative and absolute reliability need to be established. No studies have evaluated the reliability of maximal walking speed in an aged population with different medical diagnoses. Therefore, the aim of this study was to investigate the reliability of walking speed through test retest in older people living in a residential care unit.
Methods: A sample of older people living in a residential care unit was invited to participate in the study. Maximal walking speed was measured for a distance of 10 m with an acceleration and deceleration phase of 2 m each. Data were collected twice for each individual within a 1-week interval.
Results: Thirty-one subjects participated on both test occasions. The mean age was 89 years (74-100 years); 25 women and 6 men participated. The test-retest analysis showed an intraclass correlation coefficient (1,1) of 0.86 between the 2 tests. The mean value of the first occasion was 0.97 m/s (SD = 0.30 m/s), and the mean value of the second occasion was 0.95 m/s (SD = 0.29 m/s). The mean difference was -0.03 m/s (SD = 0.16 m/s), and the 95% limits of agreement for the mean difference were -0.33 to 0.27.
Discussion and Conclusion: A maximum walking speed test in institution-dwelling older people aged 65 years and older, with several different diagnoses, shows high reliability. The method is easy to perform in a clinical setting at a minimal cost and can be recommended for use in this group before and after a training period. However, the variance of -0.33 to +0.27 m/s needs to be considered when evaluating the effect of a training period.