Evaluating the predictive validity of SARC-F cut-off scores for low muscle strength among older adults in a low-income community

BACKGROUND: With an aging population, muscle health, encompassing locomotion and metabolic function, has become a public health priority. Handgrip strength is a validated surrogate measure of general muscle strength, but measurement may not be feasible in low-resource settings. The SARC-F questionnaire (Strength, Assistance in walking, Rise from a chair, Climb stairs, and Falls) provides a simple, low-cost, and practical tool for sarcopenia screening, though its optimal cut-off remains debated. OBJECTIVE: To evaluate the predictive validity of SARC-F cut-off scores in identifying low muscle strength among community-dwelling older adults in a low-income population. METHODS: We included 733 participants (221 men, 512 women; aged 60-95 years) from the Amazonas region of Brazil. All completed the SARC-F and underwent handgrip strength testing. Low handgrip strength was based on EWGSOP2 criteria (