Measurement properties of performance-based measures to assess physical function in chronic kidney disease: recommendations from a COSMIN systematic review

Background. There is wide heterogeneity in physical function tests available for clinical and research use, hindering our ability to synthesize evidence. The aim of this review was to identify and evaluate physical function measures that could be recommended for standardized use in chronic kidney disease (CKD). Methods. MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, CINAHL, Scopus and Web of Science were searched from inception to March 2022, identifying studies that evaluated a clinimetric property (validity, reliability, measurement error and/or responsiveness) of an objectively measured performance-based physical function outcomes using the COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) methodology and Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) based recommendations. Studies with individuals of all ages and of any stage of CKD were included. Results. In total, 50 studies with 21 315 participants were included. Clinimetric properties were reported for 22 different physical function tests. The short physical performance battery (SPPB), Timed-up-and-go (TUG) test and Sit-to-stand tests (STS-5 and STS-60) had favorable properties to support their use in CKD and should be integrated into routine use. However, the majority of studies were conducted in the hemodialysis population, and very few provided information regarding validity or reliability. Conclusion. The SPPB demonstrated the highest quality of evidence for reliability, measurement error and construct validity amongst transplant, CKD and dialysis patients. This review is an important step towards standardizing a core outcome set of tools to measure physical function in research and clinical settings for the CKD population. Poor physical function is very common among people living with chronic kidney disease (CKD), gets worse as the disease progresses, and is linked with reduced survival and poor quality of life. Routine assessment of physical function can help identify frailty and sarcopenia (loss of muscle mass) early on, allowing for timely introduction of therapies such as exercise rehabilitation. In this study, we reviewed the current literature to identify which physical function measures should be used to ensure that physical function is captured accurately and consistently, both in clinical practice and in research. We found that the short physical performance battery, Timed-up-and-go, Sit-to-stand-5 and Sit-to-stand-60 had good evidence to support their use in CKD. Our review and recommendations are the initial steps toward introducing a set of tools to measure physical function that can be used as part of routine CKD care. [GRAPHICS] .