General motor function assessment scale--reliability of a Norwegian version

The General Motor Function assessment scale (GMF) measures activity-related dependence, pain and insecurity among older people in frail health. The aim of the present study was to translate the GMF into a Norwegian version (N-GMF) and establish its reliability and clinical feasibility.

The procedure used in translating the GMF was a forward and backward process, testing a convenience sample of 30 frail elderly people with it. The intra-rater reliability tests were performed by three physiotherapists, and the inter-reliability test was done by the same three plus nine independent colleagues. The statistical analyses were performed with a pairwise analysis for intra- and inter-rater reliability, using Cronbach's α, Percentage Agreement (PA), Svensson's rank transformable method and Cohen's κ.

The Cronbach's α coefficients for the different subscales of N-GMF were 0.68 for Dependency, 0.73 for Pain and 0.75 for Insecurity. Intra-rater reliability: The variation in the PA for the total score was 40-70% in Dependence, 30-40% in Pain and 30-60% in Insecurity. The Relative Rank Variant (RV) indicated a modest individual bias and an augmented rank-order agreement coefficient ra of 0.96, 0.96 and 0.99, respectively. The variation in the κ statistics was 0.27-0.62 for Dependence, 0.17-0.35 for Pain and 0.13-0.47 for Insecurity. Inter-rater reliability: The PA between different testers in Dependence, Pain and Insecurity was 74%, 89% and 74%, respectively. The augmented rank-order agreement coefficients were: for Dependence r(a) = 0.97; for Pain, r(a) = 0.99; and for Insecurity, r(a) = 0.99.

The N-GMF is a fairly reliable instrument for use with frail elderly people, with intra-rater and inter-rater reliability moderate in Dependence and slight to fair in Pain and Insecurity. The clinical usefulness was stressed in regard to its main focus, the frail elderly, and for communication within a multidisciplinary team. Implications for Rehabilitation The Norwegian-General Motor Function Assessment Scale (N-GMF) is a reliable instrument. The N-GMF is an instrument for screening and assessment of activity-related dependence, pain and insecurity in frail older people. The N-GMF may be used as a tool of communication in a multidisciplinary team.