The Development of the Short-form of “25-Question Geriatric Locomotive Function Scale”

Abstract

Objectives: In 2007, the Japanese Orthopaedic Association (JOA) proposed the term “locomotive syndrome” (LS) to describe a condition in high-risk musculoskeletal disease patients who are highly likely to require nursing care. The JOA developed a screening tool, the 25-question Geriatric Locomotive Function Scale “GLFS-25” and the 5-question Geriatric Locomotive Function Scale “GLFS-5” in 2012. However, there are some issues about these screening tools. GLFS-25 has 25 questions, and complete response is needed to diagnose LS, but our previous studies revealed that the complete response rates were extremely low (50-70%). GLFS-5 which has only 5 questions and it can only screen Normal and LS, but it can’t classify Grade 1 LS and Grade 2 LS. We thought we need short-form of GLFS-25 which is easier than GLFS-25 and more accurate than GLFS-5. Methods: We developed a short-form of GLFS-25 by performing an exploratory/explanatory factor analysis (EFA) of approximately 1000 orthopaedic outpatients. We also performed confirmation studies in an additional cohort using an item response theory (IRT) analysis, a principal component analysis (PCA) and a receiver operating characteristic (ROC) analysis. Results: We used an EFA to develop a short-form of GLFS-25 (GLFS-9), which consisted of 9 questions that were included in the GLFS-25. These 9 items were graded on the 5-point scale; the total score (0–36) was used to diagnose patients with Grade 1 LS (3–5 points) or Grade 2 LS (≥6 points) LS; while No-LS (normal) was defined by a score of ≤2 points. The ability of GLFS-9 to predict LS was confirmed by an IRT analysis, a PCA, and an ROC analysis. Conclusion: We developed the GLFS-9 which can classify Grade 1 LS and Grade 2 LS, a short-form of the GLFS-25. We believe that the GLFS-9 may allow for the more accessible screening and prevention of LS.