Reliability of two gait speed tests of different timed phases and equal non-timed phases in community-dwelling older persons.

BACKGROUND

Gait speed is a fast, low cost and accurate measurement for evaluating older persons’ functional ability, both health and with comorbidities. Previous studies have evaluated gait speed measured over courses of varying distances, but the non-timed phases are not measured uniformly. It is unknown if this affects the results of the test.

OBJECTIVE

This study aims to evaluate the reliability of the running speed test of two different timed phases compared to the same nontimed phases.

METHODS

We conducted a descriptive reliability study, with an observational and cross-sectional analytical design. One hundred thirty-six older persons were included. Two gait speed tests were taken, one of 4 and 10 meters, and 2 meters for the acceleration/deceleration phase for both tests. The average of two attempts was obtained as a final measure of each test. The intraclass correlation coefficient was used to express the results (ICC) with a fixed effects model and the Bland and Altman method (confidence interval of 95%), complemented with the standard error of the mean and minimal detectable change with 95% confidence values (MDC95).

RESULTS

The results indicate an excellent level of agreement between the attempts of the tests of 4- and 10-m (ICC = 0.959 and 0.976, respectively), as well as between the average of the two tests (ICC = 0.867). The agreement was slightly better between the two attempts in the 10-meter test. The number of attempts does not affect the results of gait speed. Further analysis is required to conclude the same regarding the distance of the test (4 and 10 meters). The difference in the results of the Bland Altman analysis for the average of the 4 and 10-meter tests was 1.5945 m/s (95% confidence interval: 0.9759 to 2.2130 m/s), which is too wide and higher than the MDC95 value.

CONCLUSIONS

The ICC value was excellent in all cases, and the number of attempts does not affect the results of gait speed. However, further analysis is required to conclude the same regarding the distance of the test. There is an insufficient agreement between the two tests to allow them to be used interchangeably in populations with the characteristics of this study. .