SARC-F with anthropometric add-ons for better sarcopenia detection among elderly outpatients visiting a tertiary care hospital: A cross-sectional study

Sarcopenia is a progressive skeletal muscle disorder associated with an increased risk of falls, fractures, physical disability, frailty, and mortality [1]. Muscle weakness is often the earliest manifestation of sarcopenia; however, the condition frequently remains unrecognised in its early stages [2]. International guidelines recommend annual screening for sarcopenia in adults aged 65 years and older or following any major adverse health event.

The Strength, Assistance with walking, Rise from a chair, Climb stairs, and Falls (SARC-F) questionnaire is the most widely recommended screening tool for sarcopenia. Although it demonstrates acceptable specificity, its low-to-moderate sensitivity limits its ability to identify many individuals with the condition [3]. To improve its diagnostic performance, anthropometric measurements have been incorporated into modified screening tools. Calf girth (CalF), recommended by the Asian Working Group for Sarcopenia (AWGS) 2019 and the European Working Group on Sarcopenia in Older People, is considered a simple and reliable surrogate measure of muscle mass and has been endorsed by the World Health Organization as one of the most useful anthropometric indicators. However, calf girth may be influenced by conditions such as lower-limb edema and increased adipose tissue, potentially reducing its diagnostic accuracy [3, 4, 5]. Arm circumference (AC) is another simple anthropometric measure that correlates with muscle mass and has shown potential as a screening marker for sarcopenia. Previous studies have demonstrated that reduced AC is significantly associated with sarcopenia adults [4].

Incorporating AC into the SARC-CalF questionnaire (SARC-CalF+AC) has been reported to improve the diagnostic accuracy of sarcopenia screening in several populations [6]. Nevertheless, evidence regarding its performance remains limited, and its applicability across different populations is not well established.

In India, many studies have relied on diagnostic cut-off values derived from Caucasian populations, which may compromise diagnostic accuracy in Indian older adults [7]. The recently published Indian consensus on sarcopenia emphasises the need for region-specific diagnostic criteria, considering ethnic differences in body composition and genetic characteristics, and highlights the importance of validating simple, practical screening tools using population-specific cut-off values [8].

Therefore, this study aimed to examine the diagnostic accuracy of the SARC-F and SARC-CalF+AC questionnaires for screening sarcopenia among elderly outpatients department of a tertiary care hospital, in India.

Study design

This cross-sectional study recruited older adults attending the outpatient department of a tertiary care hospital. Participants were eligible if they were aged ≥60 years, had intact cognitive function, and were able to stand and walk independently.

Data collection

A total of 391 older adults were screened between May and December 2025, of whom 360 met the eligibility criteria. Thirty-one participants were excluded because of cognitive impairment, walking difficulty, or multiple comorbidities.

Handgrip strength was measured using a Jamar dynamometer, and the highest value from three trials performed with the dominant hand was recorded. Muscle performance was assessed using the five-times chair stand test. Calf girth was measured at its maximum circumference with the participant standing, while arm circumference was measured at the midpoint between the acromion and olecranon processes with the arm relaxed alongside the body.

Procedure

Demographic and clinical information, including age, sex, height, weight, body mass index, comorbidities, and primary diagnosis, was collected using a structured questionnaire. Sarcopenia was diagnosed based on assessments of muscle strength, muscle performance, and muscle mass in accordance with the study's diagnostic criteria. Handgrip strength was used to assess muscle strength, while the five-times chair stand test was used to evaluate muscle performance.

Table 2 Sensitivity, specificity, likelihood ratios, disease prevalence, predictive values, and accuracy for SARC-F and SARC-CalF+AC questionnaires in sarcopenia screening (n=360)

Discussion

Sarcopenia is a common age-related skeletal muscle disorder associated with reduced physical function, falls, fractures, frailty, and increased mortality. Early identification is essential for timely intervention and prevention of adverse health outcomes in the growing older population. Although the SARC-F questionnaire is the most widely recommended screening tool, its diagnostic performance varies across populations and is influenced by factors such as age, comorbidities, ethnicity, and body composition.

Previous studies have reported considerable variation in the sensitivity and specificity of the SARC-F questionnaire. For example, a study conducted in Vietnam reported a sensitivity of 65.8% and a specificity of 71.4% based on the AWGS 2019 criteria, whereas a study from Hong Kong reported high specificity (98.8% in men and 94.2% in women) but comparatively lower sensitivity [13]. These findings highlight the limited sensitivity of the SARC-F questionnaire and the need to improve its ability to identify individuals with sarcopenia.

The incorporation of anthropometric measurements into the SARC-F questionnaire has been proposed as a practical approach to improving its diagnostic performance. Previous studies from Brazil and China demonstrated that adding calf circumference to the SARC-F increased the sensitivity of sarcopenia screening [14]. Consistent with these findings, our study showed that incorporating both calf circumference and arm circumference (SARC-CalF+AC) substantially improved the sensitivity of the screening tool (75.6%) compared with the original SARC-F questionnaire (22.9%), while maintaining good specificity. These findings support the value of anthropometric measurements as simple and effective additions to conventional sarcopenia screening. The optimal arm circumference cut-off values identified in our study were lower than those reported in a Chinese population [14], emphasising the importance of population-specific cut-off values.

Appropriate diagnostic cut-off values are essential for maximizing screening accuracy. Differences in ethnicity, body composition, nutritional status, and genetic background may influence anthropometric measurements and the prevalence of sarcopenia. The recently published Indian Consensus on Sarcopenia also emphasizes the need for region-specific diagnostic criteria to improve the identification and management of sarcopenia in Indian older adults.

The SARC-CalF+AC questionnaire is a simple, inexpensive, non-invasive, and practical screening tool that can be easily implemented in routine clinical practice, particularly in primary healthcare and resource-limited settings. Its improved diagnostic performance may facilitate earlier identification of individuals at risk of sarcopenia and support timely intervention. Given the influence of socioeconomic, ethnic, and lifestyle factors on sarcopenia, further validation of this screening tool in diverse populations is warranted [2].

This study has several limitations. First, the sample size was relatively small and participants were recruited from a single tertiary care hospital, which may limit the generalisability of the findings. Second, skeletal muscle mass was estimated using Lee's predictive equation rather than direct measurement techniques such as bioelectrical impedance analysis or dual-energy X-ray absorptiometry. Third, we did not evaluate the severity of sarcopenia among affected participants. Future multicentre studies involving larger and more diverse populations and using gold-standard methods for muscle mass assessment are needed to further validate the diagnostic performance of the SARC-CalF+AC questionnaire.

Conclusion

SARC-CalF+AC showed substantially higher sensitivity than SARC-F alone for detecting sarcopenia in this Indian population, supporting its use as a practical screening tool in primary care and outpatient settings. Incorporating ethnicity-specific and socioeconomic factors into future cut-off values will further improve screening accuracy.