Diagnostic accuracy of SARC-F and SARC-CalF as sarcopenia screening instruments in rheumatoid arthritis according to European Working Group on Sarcopenia in Older People


KARAPINAR M., UĞURLU Z., GÜR HATİP F., BAŞKURT F., ŞAHİN M., DOĞRU A.

Physiotherapy Theory and Practice, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1080/09593985.2026.2627992
  • Dergi Adı: Physiotherapy Theory and Practice
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, CINAHL, MEDLINE
  • Anahtar Kelimeler: calf circumference, muscle mass, Rheumatoid arthritis, sarcopenia, screening tool
  • Süleyman Demirel Üniversitesi Adresli: Evet

Özet

Objective: This study aimed to evaluate the diagnostic accuracy of SARC-F and SARC-CalF as screening tools for sarcopenia in patients with rheumatoid arthritis using the European Working Group on Sarcopenia in Older People 2 algorithm as the reference standard. Method: A cross-sectional study was conducted among 106 patients with rheumatoid arthritis diagnosed according to the 2010 ACR/EULAR criteria. Sarcopenia was assessed through handgrip strength, appendicular skeletal muscle mass (via bioelectrical impedance analysis), and gait speed, following the EWGSOP2 “Find–Assess–Confirm–Severity” (F-A-C-S) model. The diagnostic performance of SARC-F and SARC-CalF was evaluated using sensitivity, specificity, positive and negative predictive values (PPV, NPV), and receiver operating characteristic (ROC) curves. Results: Among the participants, 43.3% had probable sarcopenia (low muscle strength), 15% had confirmed sarcopenia (low muscle strength plus low muscle mass), and 11.3% had severe sarcopenia (low strength, low mass, and poor physical performance), according to EWGSOP2 criteria. SARC-F showed high sensitivity (86.2%) and NPV (91.3%) for probable sarcopenia but had low specificity (54.5%) and poor discrimination for confirmed (AUC: 0.43) and severe (AUC: 0.44) cases. In contrast, SARC-CalF demonstrated improved specificity (90.7%) and better AUC (0.63) for confirmed sarcopenia, although sensitivity remained low (32.3%). Both tools showed limited performance in detecting severe sarcopenia. Conclusion: SARC-F, with its high sensitivity, can serve as a first-line physiotherapy screening tool to identify patients with rheumatoid arthritis at risk of sarcopenia, enabling timely referral for muscle-strengthening interventions. SARC-CalF offers greater specificity for confirmed cases and supports individualized exercise planning. As neither tool alone detects severe sarcopenia, a two-step approach combining both questionnaires with confirmatory assessments is recommended to enhance early detection and optimize functional outcomes in physiotherapy practice.