Abstract

This study aimed to address the lack of accurate and straightforward sarcopenia screening tools in Vietnamese primary care by developing and validating ViSarco, a pragmatic anthropometry-based instrument for older adults. Using a sequential mixed-methods design, we reviewed the literature and worked with frontline providers to identify feasible screening items. In the development cohort (n = 416), criterion validity was established against DEXA, handgrip strength, and gait speed, and logistic regression identified body mass index (2 points), arm circumference (1 point), and calf circumference (1 point) as the strongest predictors. External validation in a large, stratified cohort (n = 806) using multifrequency BIA confirmed consistent performance across age, sex, and urban–rural strata. A cutoff score of ≥2 yielded 77.2% sensitivity and 76.6% specificity (AUC = 0.77) in the development phase and an AUC of 0.83 with 78.0% diagnostic accuracy in validation, outperforming six international comparators. ViSarco’s novelty lies in its co-design, methodological rigor, and operational simplicity; relying solely on BMI, AC, and CC, it can be completed in minutes with negligible training and no equipment, making it well-suited for resource-limited primary care and offering a scalable model for sarcopenia screening in low-and middle-income countries.