Accuracy of Ultrasound Measurements of Muscle Thickness in Identifying Older Patients With Sarcopenia and Its Impact on Frailty: A Systematic Review and Meta-Analysis.

OBJECTIVES

The aim of this systematic review was to assess the diagnostic test accuracy of muscle ultrasound for identifying older patients with sarcopenia and to investigate its association with frailty.

DESIGN

Systematic review and meta-analysis of observational studies. Comprehensive searches were conducted in PubMed, MEDLINE, Cochrane Library, Scopus, and Embase through October 2024.

SETTING AND PARTICIPANTS

Clinical and community settings across 7 countries, with 2537 adults aged ≥65 years.

METHODS

Two reviewers assessed study quality using QUADAS-2. Data on participant characteristics, ultrasound methods, and diagnostic outcomes were extracted. Pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curve were calculated with a random-effects model. Sensitivity analyses ensured robustness.

RESULTS

Pooled sensitivity was 0.85 (95% CI, 0.78-0.93), specificity was 0.74 (95% CI, 0.65-0.81), DOR was 16.65 (95% CI, 4.90-96.67), and SROC-area under the curve was 0.87, indicating moderate to high diagnostic accuracy. Association with frailty yielded an odds ratio of 7.91 (95% CI, 6.15-10.17). Most studies received an "unclear" rating in several QUADAS-2 domains, especially in patient selection and reference standards, indicating limitations in study design that may impact the generalizability of results.

CONCLUSIONS AND IMPLICATIONS

Ultrasound is a reliable, noninvasive, and cost-effective tool for diagnosing sarcopenia in older patients. Further research should standardize cutoffs and explore integration with other methods.