Reliability and validity of the Norwegian-language version of the elderly mobility scale in older hospitalised patients.

Background and purpose: Reliable and valid assessment tools are needed to evaluate and predict physical function in older hospitalised patients. The purpose of this study was to determine the reliability and validity of the Norwegian-language version of the Elderly Mobility Scale (EMS-N) for use with geriatric patients.

Methods: Fifty patients admitted to a medical ward in a hospital in Norway were included. The inclusion criteria were acute hospital admission because of medical issues, age ≥65 years and referred to a physiotherapist for a physical function review. The original version of the Elderly Mobility Scale (EMS) was translated from English to Norwegian before initiating this study. EMS-N was tested for internal consistency, test-retest reliability and criterion validity by using the short physical performance battery (SPPB) as the gold standard. Internal consistency was measured by Cronbach's alpha. Test-retest reliability was estimated by linear weighted kappa and the intra-class correlation coefficient (ICC).

Results: The mean age of participants was 82 (range 65-95). The main admission diagnoses were acute functional decline (64%, n = 32) or acute infection (26%, n = 13). Internal consistency was estimated at 0.88. Test-retest reliability: six of the seven EMS-N items showed very good consistency, and the last item showed good consistency, ICC was estimated at 0.99. The standard error of measurement (SEM) reflected the absolute reliability, calculated at 0.52. The minimal detectable change (MDC) was calculated with 95 and 90% confidence intervals at 1.44 and 1.21, respectively. Criterion validity was calculated by a correlation analysis of the EMS-N and the SPPB. The rho value was estimated as 0.75, which corresponds to a high correlation and indicated good criterion validity.

Discussion: EMS-N exhibited good internal consistency and good to very good test-retest reliability and criterion validity. EMS can safely be used as an assessment tool for hospitalised geriatric patients.