Validity of the modified versions of SARC-F plus EBM for sarcopenia screening and diagnosis in China: the PPLSS study

Background and Objectives: It is recommended by Asian Working Group for Sarcopenia to early identify people at risk for sarcopenia using simple screening tools like SARC-F. The modified version SARC-F+EBM showed higher diagnostic performance. However, this cut-off value of body mass index (BMI) remained uncer-tain to be used in Chinese population. In this study, we used appropriate BMI recommended for Chinese older population and further modified SARC-F+EBM by combining calf circumference. Methods and Study Design: Diagnostic tests were performed and the receiver operating characteristics analyses were conducted between the SARC-F, SARC-F+EBM (cut-off of BMI: <= 21 kg/m2), SARC-F+EBM (CN) (cut-off of BMI: <= 22 kg/m2), SARC-CalF and SARC-CalF+EBM (CN) (cut-off of BMI: <= 22 kg/m(2)) in 1660 community-dwelling participants aged >= 65 years from China. Results: The participants had an average age of 71.7 +/- 5.1 years, of which 56.8% were women. All the modified models could enhance the areas under the receiver operating characteristic curve (AUC) of original SARC-F (all p<0.001). The SARC-F+EBM (CN) also showed a significantly higher sensitivity of 47.4% (p<0.001) and an AUC of 0.809 (p=0.005) than SARC-F+EBM. SARC-CalF+EBM (CN) was validated to be of great diagnostic value of the highest AUC of 0.88 among these sarcopenia screening tools, including SARC-F, SARC-CalF and SARC-F+EBM (CN) (all p<0.001). Using this study population as a reference, the op-timal cut-off value of SARC-CalF+EBM (CN) is >= 12 points, with a sensitivity of 79.3% and a specificity of 80.7%.Conclusions: The SARC-F+EBM (CN) and SARC-CalF+EBM (CN) could enhance the diagnostic per-formance of SARC-F and SARC-F+EBM and are suitable sarcopenia screening tools for Chinese population.