Performance of Five Thai Versions of Sarcopenia Screening Questionnaires (SARC-F, SARC-CalF, MSRA-7, MSRA-5, and Modified MSRA-5) in Thai Rheumatoid Arthritis Patients: A Cross-Sectional Study

<b>Background/Objectives:</b> The external validity of sarcopenia screening questionnaires in the elderly has been examined in several conditions but rarely evaluated in patients with rheumatoid arthritis (RA). This study aimed to determine the performance of five Thai versions of sarcopenia screening questionnaires (SARC-F [Strength, Assistance with walking, Rising from a chair, Climbing stairs, and Falls], SARC-CalF [SARC-F plus calf circumference], MSRA [Mini Sarcopenia Risk Assessment]-7, MSRA-5, and modified MSRA-5 questionnaires) in Thai RA patients, and evaluate the correlations among these instruments. <b>Methods</b>: In this cross-sectional study, consecutive adult RA patients (aged ≥20 years) from an outpatient rheumatology clinic completed the five sarcopenia screening questionnaires listed above. Sarcopenia was defined according to criteria of the 2019 Asian Working Group for Sarcopenia (AWGS). Appendicular skeletal muscle mass, grip strength, and physical performance were assessed using bioelectrical impedance analysis, a hand dynamometer, and a 6 m gait speed test, respectively. The cut-off values used for each sarcopenia screening questionnaire were pre-specified according to their respective established thresholds. <b>Results</b>: Of 299 RA patients (89.0% female, mean age of 61.3 ± 11.6 years, median [interquartile range] disease duration of 12.8 [8.2, 20.0] years), 37.5% and 27.4% of them had sarcopenia and severe sarcopenia, respectively. The areas under the receiver operating characteristic (ROC) curve for the SARC-F, SARC-CalF, MSRA-7, MSRA-5, and modified MSRA-5 questionnaires were 0.60, 0.74, 0.65, 0.62, and 0.65, respectively, with sensitivities of 34.8%, 73.2%, 77.7%, 68.8%, and 72.3% and specificities of 84.5%, 75.4%, 51.3%, 55.1%, and 58.3%, respectively. SARC-F demonstrated moderate correlations with the other questionnaires: SARC-CalF (r = 0.57), MSRA-7 (r = -0.52), MSRA-5 (r = -0.55), and modified MSRA-5 (r = -0.65), all with a <i>p</i>-value of <0.001. <b>Conclusions</b>: Sarcopenia is common among Thai RA patients. SARC-CalF had the best balance of sensitivity and specificity and is likely the most suitable sarcopenia screening questionnaire for Thai RA patients.