Novel Adaption of the SARC-F Score to Classify Pediatric Hemato-Oncology Patients with Functional Sarcopenia

SIMPLE SUMMARY: Children treated for hemato-oncological diseases are at risk of muscle deterioration, such as loss of muscle mass and muscle weakness, with consequent impaired physical functioning. An easy screening tool will facilitate the early identification of children at risk and will support clinical decision making. We investigated the accuracy of an easy screening tool: the pediatric SARC-F (PED-SARC-F), for identifying functional sarcopenia in pediatric hemato-oncology patients. Functional sarcopenia indicates low muscle strength combined with low physical performance. We showed that the PED-SARC-F has a 90% accuracy in identifying pediatric hemato-oncology patients with functional sarcopenia. A PED-SARC-F cut-off point of ≥5 had the highest specificity (91%) and limits unnecessary assessments in patients who are not at risk of sarcopenia. This tool can be used to identify children that need a physiotherapy assessment and further interventions to prevent physical deterioration during and shortly after treatment for a hemato-oncology disease. ABSTRACT: Sarcopenia in pediatric hemato-oncology patients is undesirable because of the consequences it may have for treatment continuation and outcome, physical abilities and participation in daily life. An easy-to-use screening tool for sarcopenia will facilitate the identification of children at risk who need interventions to prevent serious physical deterioration. In the elderly, the use of the SARC-F score as a case-finding tool for sarcopenia is recommended. The aim of this cross-sectional study was to investigate the accuracy of the pediatric SARC-F (PED-SARC-F) for identifying sarcopenia in pediatric hemato-oncology patients, including the determination of a cut-off point for clinical use. Patients 3–20 years of age, under active treatment or within 12 months after treatment cessation were eligible. Patients had a physiotherapy assessment including a PED-SARC-F (0–10) and measurements of muscle strength (handheld dynamometry), physical performance (various tests) and/or muscle mass (bio-impedance analysis), as part of the standard of care. Spearman’s correlation coefficient (r(s)) between the PED-SARC-F and physiotherapy outcomes were calculated. Structural sarcopenia was defined as low appendicular skeletal muscle mass (ASMM) in combination with low muscle strength and/or low physical performance. Functional sarcopenia indicated low muscle strength combined with low physical performance. Multiple logistic regression models were estimated to study the associations between the PED-SARC-F and structural/functional sarcopenia. To evaluate which cut-off point provides the most accurate classification, the area under the receiver operating characteristic curve (AUCs), sensitivity and specificity per point were calculated. In total, 215 assessments were included, 62% were performed in boys and the median age was 12.9 years (interquartile range: 8.5–15.8). The PED-SARC-F scores correlated moderately with the measurements of muscle strength (r(s) = −0.37 to −0.47, p < 0.001) and physical performance (r(s) = −0.45 to −0.66, p < 0.001), and weakly with ASMM (r(s) = −0.27, p < 0.001). The PED-SARC-F had an AUC of 0.90 (95% confidence interval (CI) = 0.84–0.95) for functional sarcopenia and 0.79 (95% CI = 0.68–0.90) for structural sarcopenia. A cut-off point of ≥5 had the highest specificity of 96% and a sensitivity of 74%. In conclusion, we adapted the SARC-F to a pediatric version, confirmed its excellent diagnostic accuracy for identifying functional sarcopenia and defined a clinically useful cut-off point in pediatric hemato-oncology patients.