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


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.
Department of Epidemiology and Biostatistics, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran. khalkhali@umsu.ac.ir
Hamid Reza
HR
Khalkhali
Ali
A
Ghafari
D018450:Disease Progression; D005919:Glomerular Filtration Rate / Q000502:physiology; D006084:Graft Rejection / Q000453:epidemiology* / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D007492:Iran; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000401:mortality / Q000503:physiopathology; D016030:Kidney Transplantation; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D014184:Transplantation, Homologous