3837 Diagnostic ability of SARC-F according to muscle strength and physical performance tests

Abstract Rationale Sarcopenia, the progressive loss of muscle mass and strength, increases the risk of falls, disability, and mortality in older adults. The SARC-F questionnaire is commonly used to screen for probable sarcopenia, though the optimal cut-off remains debated. This study aimed to identify the most appropriate SARC-F threshold by examining its association with measures of muscle strength and physical performance. Methods Individuals aged ≥65 years who presented to a tertiary university hospital geriatric outpatient clinic between January 2022 and May 2024, were evaluated in this cross-sectional study. Patients with active inflammatory conditions, malignancy, or incomplete datasets were excluded. SARC-F scores were analysed against established performance tests: handgrip strength (HGS; <16 kg for females, <27 kg for males), sit-to-stand (STST >15 seconds), 4-meter gait speed(>5 seconds), and the Timed Up and Go (TUG >20 seconds). Receiver operating characteristic (ROC) analyses were performed to determine diagnostic accuracy. Results Among the 3583 individuals screened, 1355 met the inclusion criteria (mean age: 74.0 ± 6.0 years; 64.9% female). A SARC-F score ≥ 4 was identified in 22.2% of participants. Using a cut-off of ≥2, sensitivity and specificity were 68.9% and 63.6% for HGS (AUC = 0.705), and 68.6% and 68.3% for STST (AUC = 0.735), respectively. A threshold of ≥3 was optimal for detecting slow gait speed (sensitivity 63.75%, specificity 83.4%, AUC = 0.788), while a cut-off of ≥4 yielded the greatest diagnostic accuracy for TUG (sensitivity 85.2%, specificity: 82.5%, AUC = 0.881). Conclusion This study, involving one of the largest single-centre geriatric outpatient cohorts, supports a lower SARC-F threshold for improved early detection of sarcopenia. A novel perspective is introduced by proposing the SARC-F as a gradational marker of sarcopenia severity and functional decline, rather than a binary outcome.