assuming a 22 per cent prevalence of renal disease requiring surgery in the azotemic population , bayes ' theorem predicts that an abnormal ultrasonic test will increase the probability of surgery in a patient with renal failure from 0.22 to 0.81 , while a negative test will reduce the probability from 0.22 to 0.013 .
C0022658
renal disease
C0035078
renal