SARC-F as a case-finding tool for sarcopenia according to the EWGSOP2. National validation and comparison with other diagnostic standards.

Background: Sarcopenia is a potentially reversible condition, which requires proper screening and diagnosis.
Aims: To validate a Polish version of sarcopenia screening questionnaire (SARC-F), and assess its clinical performance.
Methods: Cross-sectional validation study in community-dwelling subjects ≥ 65 years of age. Diagnosis of sarcopenia was based on the 2018 2nd European Working Group on Sarcopenia in Older People (EWGSOP2) consensus. Hand grip and 4-m gait speed were measured, and the Polish version of SARC-F was administered.
Results: The mean (SD) age of 73 participants (21.9% men) was 77.8 (7.3) years. Seventeen participants (23.3%) fulfilled the EWGSOP2 criteria of sarcopenia, and 9 (12.3%) criteria for severe sarcopenia. Fourteen (19.2%) participants fulfilled the SARC-F criteria for clinical suspicion of sarcopenia. The Cronbach's alpha coefficient for internal was 0.84. With EWGSOP2 sarcopenia as a gold standard, the sensitivity of SARC-F was 35.3% (95% CI 14.2-61.7, p = 0.33), specificity was 85.7% (95% CI 73.8-93.6, p < 0.0001). The corresponding positive and negative predictive values were 42.9% (p = 0.79) and 81.4% (p < 0.0001), respectively. The probability of false-positive result was 14.3% (95% CI 6.4-26.2, p < 0.0001) and the probability of false-negative result was 64.7% (95% CI 38.3-85.8, p = 0.33). Overall the predictive power of SARC-F was low (c-statistic 0.64).
Discussion: SARC-F is currently recommended for sarcopenia case finding in general population of older adults. However, its sensitivity is low, despite high specificity.
Conclusions: At present SARC-F is better suited to rule out sarcopenia then to case-finding. Further refinement of screening for sarcopenia with the use of SARC-F seems needed.