Objectives: To validate the SARC-F questionnaire for sarcopenia screening in musculoskeletal disease setting, and to assess improvements in diagnostic accuracy by adding "EBM" (elderly and body mass index information) to the SARC-F.
Design: Diagnostic accuracy study.
Setting and participants: The center involved in this study was located in an urban area of Kobe City, Japan. People with musculoskeletal disease in the knee, hip, or spine who were scheduled for surgical treatment were included.
Measurements: Sarcopenia was evaluated using the Asian Working Group for Sarcopenia (AWGS) and the European Working Group on Sarcopenia in Older People (EWGSOP2), which included bioimpedance, handgrip strength, and gait speed. Patients answered the SARC-F questionnaire and their body mass index was measured. SARC-F and "EBM" information were combined into an original score. The sensitivities, specificities, and areas under the receiver operating characteristic curve (AUC) were estimated and compared to identify sarcopenia.
Results: A total of 959 patients were included. Sarcopenia by AWGS criteria was identified in 36 (3.8%) patients. SARC-F had a sensitivity of 41.7% and specificity of 68.5%. SARC-F+EBM had a sensitivity of 77.8% and specificity of 69.6%, with substantial improvement in sensitivity (P<0.001). The AUCs for SARC-F and SARC-F+EBM were 0.557 (95% confidence interval [CI] 0.452-0.662) and 0.824 (95% CI 0.762-0.886), respectively (P<0.001). Similar results were obtained when EWGSOP2 criteria were used as the reference standard.
Conclusion: The SARC-F alone is not adequate for finding cases in musculoskeletal disease settings. SARC-F+EBM significantly improved the sensitivity and overall diagnostic accuracy of the SARC-F for screening sarcopenia. SARC-F+EBM is potentially useful for screening sarcopenia in different ethnic and disease settings.
Keywords: Sarcopenia; diagnostic accuracy; muscle mass.