Dialysis and transplantation have prolonged the life expectancy of all patients with advanced renal failure, and made the timing of the fatal prognosis less predictable. For example, over half of the best-matched kidney transplants are still working after twenty-five years; patient survival is even longer for those patients. Dialysis patient survival can also exceed two decades for some individuals. But for the ESRD population as a whole, average life expectancy from the time of onset of renal failure is only 4 to 5 years. For most patients renal failure remains a terminal illness.