Prediction of long-term kidney failure in renal transplant with chronic allograft dysfunction using stage-specific hazard rates

The process of kidney failure in renal
transplant recipients with chronic allograft
dysfunction is characterized by a progressive decline
in glomerular filtration rate over time that it is
determined by the 5-stage model. This study used
stage-based statistical survival analysis to predict
graft survival in renal transplant recipients with
chronic allograft dysfunction.
Materials and Methods: In a single-center,
retrospective study, 214 renal transplant recipients
with chronic allograft dysfunction were investigated
at a university hospital in Iran from 1997 to 2005. At
each patient visit, kidney function was assessed using
glomerular filtration rate and stage of disease.
Results: The estimated stage-specific hazard rates of
disease progression are stage one, 453.936; stage
two, 485.040; stage three, 545.808; and stage four;
649.488 per 1000 person-years. The estimated mean
times in each stage were as follows: kidney damage
with normal or increased glomerular filtration rate,
26.43 months; kidney damage with mildly decreased
glomerular filtration rate, 24.74 months; moderate
kidney disease, 21.98 months; and severe kidney
disease; 18.48 months. These estimates yield a mean
time from stage 1 to kidney failure of 91.63 months.
The probability of graft survival was predicted using
estimated stage-specific hazard rates. The 18th, 58th,
118th, and 155th months’ death-censored graft
survival probabilities were 0.99, 0.75, 0.25, and 0.10.
Conclusions: In this method of survival analysis, we
can determine a statistical model according to a real
clinical model in renal transplant recipients with
chronic allograft dysfunction. It enables us to
determine the stage-specific hazard rates of disease
progression. These findings can help nephrologists to
understand the kidney disease process and better
predict graft survival.