Comparing SARC-F with SARC-CalF to Screen Sarcopenia in Community Living Older Adults

Objective: To compare the diagnostic value of the SARC-F combined with calf circumference (SARC-CalF) with the standard SARC-F to screen sarcopenia in community-dwelling older adults.

Design: Cross-sectional, diagnostic accuracy study.

Setting: Geriatric outpatient clinic of a university hospital.

Participants: Older adults >= 65 years.

Measurements: Muscle mass (bioimpedance analysis device), muscle strength (hand grip strength-Jamar hydraulic hand dynamometer), and physical performance (usual gait speed). Four currently used diagnostic criteria [European Working Group on Sarcopenia in Older People (EWGSOP), Foundation for the National Institutes of Health (FNIH), International Working Group on Sarcopenia (IWGS), and Society on Sarcopenia Cachexia and Wasting Disorders (SCWD) criteria] were applied. SARC-CalF was performed by using two different calf circumference threshold: standard cut-off 31 cm (SARC-CalF-31) and national cut-off 33 cm (SARC-CalF-33). The sensitivity/specificity analyses of the SARC-CalF and SARC-F tools were run. We used the receiver operating characteristics curves and the area under the receiver operating characteristics curves (AUC) to compare the diagnostic accuracy to identify sarcopenia.

Results: We included 207 subjects; 67 male and 140 female with a mean age of 74.6±6.7 years. The prevalence of sarcopenia ranged from 1.9% to 9.2%. The sensitivity of SARC-F was between 25% (EWGSOP) and 50% (IWGS); specificity was about 82%. For SARC-CalF-31 and SARC-CalF-33 sensitivity was in general similar -between 25-50%- which pointed out that SARC-CalF was not superior to SARC-F for sensitivity in this sample. Corresponding specificities for SARC-CalF-31 and SARC-CalF-33 were higher than SARC-F and were between 90-98%. Additionally, the AUC values, which indicates the diagnostic accuracy of a screening test, were in general higher for SARC-CalF-33 than the SARC-F and SARC-CalF-31.

Conclusions: We reported that addition of calf circumference item to SARC-F tool improved the specificity and diagnostic accuracy of SARC-F but it did not improve the sensitivity in a community-dwelling Turkish older adult population sample that had low prevalence of sarcopenia. The performance of SARC-CalF tool to screen sarcopenia is to be studied in different populations and living settings.