Development of a Japanese version of the SARC-F for diabetic patients: an examination of reliability and validity

Background SARC-F is a 5-item, self-administered questionnaire developed to screen sarcopenia. To date, no Japanese version of the SARC-F has been developed. Aims To create a Japanese version of the SARC-F (SARC-F-J), a questionnaire for diabetic patients, and to investigate its reliability and validity. Methods This was a cross-sectional study. A Japanese translation of the SARC-F was created and revised, and the authors of the original version of the SARC-F verified the back-translation. The questionnaire was tested in diabetic outpatients aged >= 65 years who had received treatment at our hospital. After 14 weeks, the kappa coefficient was used to evaluate the retest reliability. Using the diagnostic criteria for sarcopenia based on the European Working Group on Sarcopenia in Older People as the reference standard, we calculated the sensitivity, specificity, positive predictive value, and negative predictive value of the SARC-F-J. Results The study comprised 207 patients (men, 60.8%; women, 39.2%). The kappa coefficient was 0.66. For men and women, the sensitivities were 14.6 and 33.3%, specificities were 85.8 and 72.4%, positive predictive values were 33.3 and 17.3%, and negative predictive values were 65.7 and 86.2%, respectively. Discussion The probability of identifying the condition is considered high when patients are diagnosed with sarcopenia using SARC-F-J. Conclusions The retest reliability of SARC-F-J was regarded to be good. When EWGSOP was assumed as a reference, the specificity of SARC-F-J was high. Because the sensitivity was low, patients with sarcopenia could not be screened, and hence, attention is needed.