SARCORSICA: SARC-F Questionnaire as a Screening Tool for Age-related Sarcopenia

Background to the research: Sarcopenia is a multifactorial geriatric syndrome with a prevalence ranging between 1 and 29% depending on age. It is defined by progressive, generalised loss of skeletal muscle, mass, force and function.

Problem statement and objectives: To confirm a simple, reproducible, screening tool, which is easy to use in the general practitioner's surgery is one of the challenges of the future.

The primary objective is to assess the sensitivity and specificity of the study screening test, the SARC-F, at a predetermined threshold of >=4 and to change this threshold using a ROC curve to attempt to increase its sensitivity. This questionnaire has been shown to provide low sensitivity (4%-10%) but high specificity (94%-99%) in the study carried out by Woo and co-workers on an analysis of statistical performance of the questionnaire, stratified by sex. A total score of >= 4 is associated with poor physical performance and is also predictive of the clinical diagnosis of the disease. The test will be assessed compared to the clinical diagnosis of the disease using international criteria recognised by EWGSOP, which defines sarcopenia as a reduction in muscle mass, associated with a reduction in muscle force and/or reduced physical performance by the subject. The secondary objectives are to assess the prevalence of sarcopenia in the study population, to carry out a sub-group analysis of the statistical performance of the five questions tested by the SARC-F and to identify the main risk factors associated with the disease and finally to propose an algorithm positioning the SARC-F at the heart of a systematic screening process for the disease.

Materials and Methods: This is a diagnostic, cross-sectional study with a descriptive and analytical epidemiological component to analyse the secondary end points. It will be carried out in usual care over a period of 6 months. The study will be conducted in Southern Corsica in a homogeneous population of 65 year old and older patients from the community, consulting in primary care. The number of subjects required is calculated for a disease prevalence set at 15%, a 95% specificity for the screening test with a minimum acceptable confidence interval of 80%. A total of 366 patients will therefore need to be included. The subjects will undergo the screening test (SARC-F questionnaire) and then the reference clinical assessment (gold standard) in succession). Muscle force will be assessed using a dynamometer, physical performance by a 4-metre gait test and brachial muscle circumference (BMC) will be calculated from two simple anthropometric measurements, the tricipital skin fold thickness (TS) and the brachial perimeter (BP).

Expected results: To demonstrate the statistical tests that the SARC-F questionnaire is a simple tool, appropriate for early screening of sarcopenia in primary care; to define a new optimal threshold achieving greater sensitivity, to make practitioners aware of screening for sarcopenia, to improve its prevention and to promote its management as early as possible.