Reliability, validity and minimal detectable change of 2-min walk test and 10-m walk test in frail older adults receiving day care and residential care

Background The psychometric properties of the 2-min walk test (2MWT) and 10-m walk test (10MeWT) for frail older adults are unclear. Aims To determine the test-retest and inter-rater reliability, construct and known-group validity, and minimal detectable change at 95% level of confidence (MDC95) of these walk tests in frail older adults receiving day care and residential care services. Methods A cross-sectional study with repeated measures was conducted on frail older adults who could walk independently for at least 15 m. The participants completed the 2MWT and 10MeWT on three separate occasions over a 2-week period under two independent assessors. Results Forty-four frail older adults were examined. Excellent test-rest (ICC = 0.95-0.99) and inter-rater reliability (ICC = 0.95-0.97) were shown in both walk tests. Good to strong correlations were found between the walk tests and 6-min walk test (r = 0.89-0.92), Elderly Mobility Scale (r = 0.56-0.57), Berg Balance Scale (r = 0.66-0.66) and Modified Barthel Index (r = 0.55-0.59). The MDC95 were 7.7 m in the 2MWT and 0.13 m/s in the 10MeWT. Discussion Although the walking performances of the day care and residential care participants were similar, the validity of the walk tests was different between these two subgroups. Conclusions The 2MWT and 10MeWT are reliable and valid measures in evaluating the walking performances of frail older adults. The MDC95 of the walk tests has been recommended.