Supplementary Material for: Limitations of SARC-F as a Screening Tool for Sarcopenia in Patients on Hemodialysis

<b><i>Introduction:</i></b> There are limited screening tools for sarcopenia in patients undergoing hemodialysis. This study aimed to investigate the reliability and validity of the SARC-F (Strength, Assistance in walking, Rise from a chair, Climb stairs, and Falls) questionnaire as a screening tool for sarcopenia (defined by the Asian Working Group for Sarcopenia [AWGS2019]) in patients undergoing hemodialysis. <b><i>Methods:</i></b> This cross-sectional study enrolled 179 patients (mean age: 66.5 ± 12 years, 58% men) undergoing maintenance hemodialysis 3 times per week at a hemodialysis center in Japan. The SARC-F score, handgrip strength, usual gait speed, sit-to-stand test time, short physical performance battery (SPPB), and appendicular skeletal muscle mass were evaluated. The reliability and validity of the SARC-F were analyzed using receiver-operating characteristic curve, area under the curve (AUC), and sensitivity/specificity analyses. <b><i>Results:</i></b> There were 49 (27.4%) patients with sarcopenia. Patients with SARC-F ≥4 (59 patients, 33.0%) had poorer grip strength, lower SPPB score, and slower gait speed than those with SARC-F &lt;4, while the skeletal muscle mass index did not differ significantly between the two groups. The sensitivity and specificity values of the SARC-F for identifying sarcopenia were 42.9% and 70.8%, respectively, while those for identifying severe sarcopenia were 66.7% and 72.3%, respectively. The AUCs of SARC-F were 0.57 for sarcopenia and 0.70 for severe sarcopenia. <b><i>Discussion/Conclusion:</i></b> The SARC-F alone is an inadequate screening tool for sarcopenia in patients undergoing hemodialysis. It should be used in combination with objective assessment measures, rather than as a first-step screening tool, to diagnose sarcopenia.