Changes in Frailty After Kidney Transplantation

Objectives To understand the natural history of frailty after an aggressive surgical intervention, kidney transplantation ( KT ). Design Prospective cohort study (December 2008–March 2014). Setting Baltimore, Maryland. Participants Kidney transplantation recipients (N = 349). Measurements The Fried frailty score was measured at the time of KT and during routine clinical follow‐up. Using a Cox proportional hazards model, factors associated with improvements in frailty score after KT were identified. Using a longitudinal analysis, predictors of frailty score changes after KT were identified using a multilevel mixed‐effects Poisson model. Results At KT , 19.8% of recipients were frail; 1 month after KT , 33.3% were frail; at 2 months, 27.7% were frail; and at 3 months, 17.2% were frail. On average, frailty scores had worsened by 1 month (mean change 0.4, P < .001), returned to baseline by 2 months (mean change 0.2, P = .07), and improved by 3 months (mean change −0.3, P = .04) after KT . The only recipient or transplant factor associated with improvement in frailty score after KT was pre‐ KT frailty (hazard ratio = 2.55, 95% confidence interval (CI) = 1.71–3.82, P < .001). Pre‐ KT frailty status (relative risk (RR) = 1.49, 95% CI = 1.29–1.72, P < .001), recipient diabetes mellitus (RR = 1.26, 95% CI = 1.08–1.46, P = .003), and delayed graft function (RR = 1.22, 95% CI = 1.04–1.43, P = .02) were independently associated with long‐term changes in frailty score. Conclusion After KT , in adult recipients of all ages, frailty initially worsens but then improves by 3 months. Although KT recipients who were frail at KT had higher frailty scores over the long term, they were most likely to show improvements in their physiological reserve after KT , supporting the transplantation in these individuals and suggesting that pretransplant frailty is not an irreversible state of low physiological reserve.