Reliability of walking speed in basic and complex conditions in healthy, older community-dwelling individuals

Reliability of walking speed in basic and complex conditions in healthy, older community-dwelling individuals:

Abstract

Background

There is a paucity of reliability data for walking speed tests in complex conditions to assess functioning in healthy older individuals.

Aims

To evaluate the absolute intra- and intertest reliability of walking speed performed in basic and complex conditions in healthy older individuals.

Methods

Fifty-two men and women of mean age 69.7 ± 3.2 years were tested for habitual and maximal walking speed. Maximal speed was also assessed under different conditions, including walking on a path of reduced width; picking up objects; stepping over hurdles; stepping over hurdles wearing sunglasses and finally, carrying a box. Two testing sessions (separated by 4 weeks) of two trials each were administered. Reliability was analysed by intra-class correlation coefficient (ICC), minimal detectable change (MDC) and Bland–Altman plots with limits of agreement (LOA).

Results

Intrasession ICCs ranged from good to excellent (0.89–0.95) except for picking up objects (0.44). Intersession ICCs were moderate to good (0.60–0.78) and %MDCs were acceptable (14–24%). Bland–Altman plots suggested a good agreement between the two testing sessions at group level (mean differences from – 0.02 to − 0.11 m/s), and limited agreement between testing sessions at individual level (upper LOA from 0.13 to 0.37 m/s and lower LOA from − 0.29 to − 0.49 m/s).

Conclusions

Complex walking speed tests are generally reliable measures displaying good and moderate intra- and inter-session reliability. Such tests seem a more suitable functional assessment tool for heathy older subjects compared with simple walking. Some learning effect may be present and further reliability studies are needed.