The aim of this study was to examine the intra-day and inter day reliabilities of muscle strength assessment among older adults with dementia.
This study included 20 female older adults with a Mini Mental State Examination score ≧10: 10 with dementia and 10 without dementia. Knee extension muscle strength was measured three times/day, every other day for three days/week using the H-fixation method with a hand-held dynamometer. Intra-day and inter-day reliabilities were verified using the intra-class correlation coefficient, and the presence of systematic error was verified using Bland-Altman analysis. Statistical analyses were performed using R version 4.1.3 with a significance level of 5%.
The intra-day reliability value of muscle strength measurement > 0.94 in dementia adults. Similarly, the inter-day reliability value of muscle strength measurement > 0.96 in dementia adults, with both intra-day and inter-day equivalent to those of non-dementia adults. Systematic errors analyses showed significant differences in fixed errors of inter-day reliability in the group with dementia only between days 1 and 2 (p=0.01) and between days 1 and 3 (p=0.04) at 13:00, with %MDC of 19.8% and 17.1%, respectively. No other fixed or proportional errors in intra-day and inter-day reliability were observed.
Muscle strength assessment for knee extension in older adults with dementia was highly reliable, regardless with dementia or without. Future studies with larger sample sizes are needed to examine the validity in the progression of dementia, and there is also intra-rater reliability as well as inter-rater reliability.
It is significant that muscle strength assessment in older adults with dementia was as reliable as in non-dementia. Many physiotherapy assessments often have subject co-operation, and the fact that a certain degree of reliability was achieved in older adults with dementia suggests that this may be useful in the future.
Muscle strength assessment
Reliability
