Clinical usefulness of the SARC-F questionnaire to assess sarcopenia in patients with Parkinson's disease.

ABSTRACT

OBJECTIVE: To investigate the accuracy of the SARC-F questionnaire to identify sarcopenia in patients with Parkinson's disease (PD). METHODS: We prospectively recruited patients with PD who had a score of 3 or lower on the Hoehn and Yahr (H&Y) scale. Appendicular skeletal muscle mass (ASM), hand grip strength, and the SARC-F were used to assess sarcopenia. The cutoffs for the ASM index and hand grip strength to diagnose sarcopenia were based on the Asian Working Group for Sarcopenia 2019 consensus. A score ≥4 on the SARC-F was considered at risk for sarcopenia. RESULTS: A total of 365 patients with PD were included (mean age, 71.1 years; men, 53.2 %), and 73 (20.0 %) were diagnosed with sarcopenia. The area under the receiver operating characteristic curve of the SARC-F was 0.702 (95 % confidence interval, 0.634-0.770). Using the recommended cutoff score of ≥4, the SARC-F showed a sensitivity of 38.4 %, specificity of 85.6 %, positive predictive value (PPV) of 40.0 %, and negative predictive value (NPV) of 84.7 %. The Youden's index was the highest at a cutoff score of ≥2, in which the SARC-F showed a sensitivity of 67.1 %, specificity of 65.4 %, PPV of 32.7 %, and NPV of 88.8 %. These predictive values were similar to those obtained using a cutoff score of ≥2.5 or 3 on the H&Y scale. CONCLUSION: The application of the SARC-F to the mild-to moderate PD population is not appropriate as a first-step screening tool to diagnose sarcopenia. Given the comparable predictive values of the SARC-F and H&Y scale, this questionnaire may be considered only for ruling out sarcopenia in patients with similar disease severity.