The Short Physical Performance Battery (SPPB) test is an objective measurement of lower extremity function (walk speed, balance, chair stands). SPPB impairment is associated with longer length of stay and increased mortality in kidney transplant (KT) recipients. Furthermore, the SPPB test may represent an objective quantification of the ‘foot of the bed test’ utilized by clinicians; therefore, impairment may translate with decreased access to KT.
We studied 3,255 participants (2009-2018) at two KT centers. SPPB impairment was defined as a score of ≤10. We estimated time to listing, waitlist mortality, and transplant rate by SPPB impairment status using Cox proportional hazards, competing risks, and Poisson regression.
The mean age was 54 years (SD=14; range 18-89) and 54% had SPPB impairment. Impaired participants were less likely to be listed for KT (adjusted hazard ratio:0.70, 95%CI:0.64-0.77, p<0.001). Also, once listed, impaired candidates had a 1.6-fold increased risk of waitlist mortality (adjusted subhazard ratio:1.56, 95%CI:1.18-2.06, p=0.002). Furthermore, impaired candidates were transplanted 16% less frequently (adjusted incidence rate ratio:0.84, 95%CI:0.73-0.98, p=0.02).
SPPB impairment was highly prevalent in KT candidates. Impaired candidates had decreased chance of listing, increased risk of waitlist mortality, and decreased rate of KT. Identification of robust KT candidates and improvement in lower extremity function are potential ways to improve survival on the waitlist and access to KT.
1Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD.
2Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.
3Department of Medicine, Division of Nephrology, University of Michigan, Ann Arbor, MI.
4Department of Medicine, Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, MD.
Funding for this study was provided by the National Institute of Diabetes and Digestive and Kidney Disease and the National Institute of Aging: grant numbers F32AG053025 (PI: Haugen), K24DK101828 (PI: Segev), R01AG055781 (PI: McAdams-DeMarco), and R01DK114074 (PI: McAdams-DeMarco).
DISCLOSURES: Authors have no conflict of interest to report as described by Transplantation.
Contact Information: Mara McAdams-DeMarco, Ph.D., Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health , 615 N. Wolfe St, W6033, Baltimore, MD 21205, (410) 502-1950 firstname.lastname@example.org