GripBMI – A fast and simple sarcopenia screening tool in post acute inpatient rehabilitation

Abstract

Sarcopenia is prevalent in post acute inpatient rehabilitation. An easy to administer screening test may improve identification of sarcopenia in this population, which may promote its early detection and treatment. THE AIMS OF THIS STUDY WERE: a) To investigate clinical utility of SARC-F as a European Working Group on Sarcopenia in Older People2 (EWGSOP2) recommended tool for sarcopenia case finding in post acute inpatient rehabilitation. b) To develop an easy and pragmatic screening test for sarcopenia in healthcare settings with limited ability to measure the patients' muscle mass for confirmation of the sarcopenia diagnosis. This cross-sectional study with prospective data collection recruited patients admitted to a general inpatient rehabilitation unit in a metropolitan tertiary referral hospital in Australia. Participant's true sarcopenia status was ascertained, as per EWGSOP2, from their grip strength and muscle mass. Two SARC-F questionnaires were administered, for participants' current and, by recall, premorbid status. To develop GripBMI screening tool, BMI test positivity cut off was established on training sample and validated in conjunction with the established grip strength cut off on validation sample using area under the Receiver Operating Curve (ROC) analysis. True prevalence of sarcopenia in 277 participants (median age 64 years (IQR 53-72), 52% male) was 14% (95%CI 11%-19%). Screening utility of SARC-F positive status at the time of admission for sarcopenia had ROC of 0.50, and of premorbid SARC-F positive status had ROC of 0.51. Out of 42 participants positive on the GripBMI screen, 33 had sarcopenia, and out of 235 participants negative on the GripBMI screen, 7 participants had sarcopenia, resulting in GripBMI ROC area 0.89, sensitivity 83%, specificity 96%, positive predictive value 79%, negative predictive value 97%, diagnostic odds ratio 119 (95% CI 42-338). The GripBMI screening tool uses the combination of EWGSOP2 recommended low grip strength cut offs and Body Mass Index of less than 25 as a positive screening test for sarcopenia. It may assist in promoting early detection and management of sarcopenia in post acute inpatient rehabilitation.