Enhancing sarcopenia screening: Evaluating the reliability and validity of the SARC-CalF Questionnaire among community-dwelling older adults

ABSTRACT Background: Early identification of sarcopenia is crucial for improving health outcomes among older adults. While the SARC-F questionnaire offers quick screening, its limited sensitivity may result in missed diagnoses. Incorporating calf circumference measurements (SARC-CalF) may enhance screening performance, though data on this enhancement remains scarce. Objectives: This cross-sectional study aimed to assess the reliability and concurrent validity of SARC-CalF questionnaire in identifying sarcopenia among community-dwelling older adults. Methods: Reliability of SARC-CalF was evaluated through internal consistency (Cronbach’s alpha), while concurrent validity was assessed by comparing it to the Asian Working Group for Sarcopenia (AWGS) 2019 criteria. Results: A total of 195 participants (mean age 69 ± 6 years) were recruited. The prevalence of sarcopenia was 19.5% (AWGS 2019 criteria) and 17.4% (SARC-CalF). The SARC-CalF questionnaire exhibited moderate internal consistency (Cronbach’s alpha = 0.67) and concurrent validity, with a specificity of 87.9%, sensitivity of 39.5%, and area under the curve (AUC) of 0.70. Despite variations in sensitivity and specificity, higher accuracy in younger (60–69 years) and obese adults, and higher sensitivity in older (70–84 years) and underweight adults, the moderate AUC values across subgroups confirm its robustness for community sarcopenia screening. A cut-off of 7, derived from ROC curve analysis, improved the sensitivity and specificity of SARC-CalF to 55.3% and 84.7%, enhancing positive predictive agreement from 44.1% to 46.7%, and negative predictive agreement from 85.7% to 88.7%. Conclusion: The SARC-CalF questionnaire demonstrates consistent diagnostic performance across age groups, sexes, ethnicities and weight categories, underscoring it a valuable tool for sarcopenia screening among older adults in diverse population.