The identification of probable sarcopenia in early old age based on the SARC-F tool and clinical suspicion: findings from the 1946 British birth cohort

Purpose The European Working Group on Sarcopenia in Older People 2 (EWGSOP2) consensus definition introduced the concept of probable sarcopenia as a basis on which to begin treatment. Our aims were to describe the prevalence of probable sarcopenia in older adults and to investigate the utility of (1) the SARC-F tool and (2) clinical risk factors for the identification of those likely to have probable sarcopenia. Methods We used data from the 1946 British birth cohort at age 69, with 1686 participants included in the analyses. We used the EWGSOP2 cut points for weak grip strength and slow chair rise time, with the presence of one or both indicating probable sarcopenia. We examined the sensitivity and specificity of the SARC-F tool for probable sarcopenia. We also examined associations between clinical risk factors and probable sarcopenia. Results The prevalence of probable sarcopenia was 19%. A SARC-F score of >= 4 had low sensitivity (15%) and high specificity (99%) for probable sarcopenia, whereas a score of >= 1 had higher sensitivity (65%) and reasonable specificity (72%). Three clinical risk factors were independently associated with probable sarcopenia: polypharmacy [OR 2.7 (95% CI 1.7, 4.2)], lower body osteoarthritis [OR 1.8 (95% CI 1.3, 2.6)] and physical inactivity [OR of 2.1 (95% CI 1.5, 2.8)]. Conclusion We have shown that EWGSOP2 probable sarcopenia is common in community-dwelling adults in early old age. Those with any positive responses to the questions in the SARC-F tool, a history of polypharmacy, lower body osteoarthritis or physical inactivity should be prioritised for the assessment of muscle strength. Key summary pointsAim To describe the prevalence of probable sarcopenia in a sample of older adults and to investigate (1) the SARC-F tool and (2) clinical risk factors in the identification of probable sarcopenia. Findings The prevalence of probable sarcopenia at age 69 was 19%, and a SARC-F score of >= 1 had a reasonable balance of sensitivity (65%) and specificity (72%) for probable sarcopenia. Three clinical risk factors were independently associated with probable sarcopenia: polypharmacy, lower body osteoarthritis and physical inactivity. Message Those with any positive responses to the questions in the SARC-F tool, a history of polypharmacy, lower body osteoarthritis or physical inactivity should be prioritised for the assessment of muscle strength.