Diagnostic accuracy and clinical utility of simple screening strategies for sarcopenia in postmenopausal women: a cross-sectional internal evaluation study

Abstract

Simple and feasible screening strategies are needed to identify sarcopenia in postmenopausal women, particularly in settings where comprehensive body composition or functional assessment may not be readily available. This study aimed to compare the diagnostic accuracy and clinical utility of screening strategies based on arm circumference, calf circumference, and the SARC-F questionnaire for identifying Asian Working Group for Sarcopenia (AWGS)-defined sarcopenia in postmenopausal women. A total of 794 postmenopausal women were recruited from Boai Hospital in Zhongshan between January 1, 2022, and December 31, 2023. Sarcopenia was defined according to the 2019 Asian Working Group for Sarcopenia consensus criteria. The dataset was randomly divided into a development set and an internal test set at an 80:20 ratio. Five screening strategies based on arm circumference, calf circumference, SARC-F, and their combinations were evaluated. Receiver operating characteristic curve analysis was used to assess discrimination, and the area under the curve (AUC) was calculated for each strategy. Calibration analysis and decision curve analysis were performed to evaluate agreement and potential clinical utility. Among the 794 postmenopausal women, 59 met the AWGS-defined criteria for sarcopenia. In the development set, calf circumference-based strategies showed numerically higher AUCs than arm circumference or SARC-F alone. The combinations of calf circumference plus SARC-F and arm circumference plus calf circumference plus SARC-F both achieved an AUC of 0.884 in the development set. In the internal test set, calf circumference plus SARC-F and the combination of all three tools showed favorable discrimination, with AUCs of 0.921 and 0.918, respectively. Calibration analysis showed acceptable agreement between estimated and observed sarcopenia status, and decision curve analysis suggested potential net benefit across low-to-moderate threshold probabilities. Adding arm circumference to calf circumference and SARC-F resulted in a similar AUC. Calf circumference-based combined screening strategies showed favorable internal diagnostic performance for identifying AWGS-defined sarcopenia in this single-center cohort of postmenopausal women. CC + SARC-F and AC + CC + SARC-F showed similar numerical AUCs. Given its use of fewer components, CC + SARC-F may represent a practical preliminary screening approach in resource-limited settings. However, external validation in larger multicenter cohorts is required before routine clinical implementation.