Physical Impairment and Access to Kidney Transplantation

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 3255 participants (2009-2018) at 2 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.