Clinical validation of SARC-F by proxy as a practical tool to evaluate sarcopenia in dependent older adults


Ozkok S., Ören Çelik M. M., Aydin C. O., Özalp H., Kılıç C., Koc Y., ...More

JOURNAL OF GERIATRIC ONCOLOGY, vol.14, no.8, 2023 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 14 Issue: 8
  • Publication Date: 2023
  • Doi Number: 10.1016/j.jgo.2023.101630
  • Journal Name: JOURNAL OF GERIATRIC ONCOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, MEDLINE
  • Keywords: Dependent, Older adults, Proxy, SARC-F, Sarcopenia, Screening
  • Istanbul University Affiliated: Yes

Abstract

Introduction: Sarcopenia is a prevalent disorder in older adults with significant adverse outcomes and regular screening is recommended for those at risk. The SARC-F questionnaire is the most commonly recommended screening tool for sarcopenia. However, as a self-reported tool, it cannot be applied to dependent individuals with communication problems. We hypothesized that implementation of the proxy-reported SARC-F (SARC-F by proxy) would be non-inferior in screening sarcopenia when compared with the standard SARC-F. Thus, we aimed to investigate the clinical validity of the SARC-F by proxy in identifying sarcopenia in older adults and to compare its performance with the standard SARC-F. Additionally, we aimed to determine the ideal cut-off of SARC-F by proxy in screening sarcopenia. Materials and Methods: This is a validation study including older adults aged >= 60 years without communication problems and their close proxies. The participants were recruited from a geriatric outpatient clinic of a tertiary health center and a nursing home. Standard SARC-F was transformed to SARC-F by proxy and administered to the proxies of older adults, and standard SARC-F was administered to the patients simultaneously in different rooms. We defined sarcopenia as probable and confirmed by the EWGSOP2 consensus report. We performed receiver operating characteristics (ROC) and sensitivity/specificity analyses of SARC-F by proxy for diagnosing sarcopenia and compared its performance with standard SARC-F by the DeLong test. Results: We included 172 older adults (median age: 72; 44.8% female) and 107 proxies in close contact (median age: 55, 63.2% female). The prevalence of probable and confirmed sarcopenia was 18.9% and 12.9%, respec-tively. For both definitions, area under the curve (AUC) values of SARC-F by proxy and standard SARC-F were moderate and similar [probable sarcopenia: 0.619 and 0.624 (p = 0.9); confirmed sarcopenia 0.613 and 0.645 (p = 0.7), respectively]. The best balance between sensitivity and specificity was achieved with a SARC-F by proxy score of >= 2 for both sarcopenia definitions (sensitivity levels were 74.7% and 77.8%, and specificity levels were 50.0% and 49.6%, for probable and confirmed sarcopenia, respectively). Discussion: SARC-F by proxy showed a similar, non-inferior performance compared to the standard SARC-F in the evaluation of sarcopenia. Our results suggest that it can be used instead of standard SARC-F to screen sarcopenia in older patients with communication problems. Further validation studies in different populations are warranted to support our findings.