—Dr Mackow raises questions about possible biases in our comparison of survival probabilities in dialysis patients vs cadaveric renal transplant recipients based on the Michigan Kidney Registry. Although this study reduced the major biases of previous studies, including patient selection and time to transplant, while describing the early vs late risk following transplantation, there is no design that can eliminate all biases except the prospective randomized approach, which is not feasible for this comparison.The results that Mackow finds to be the most surprising appear more plausible when one considers that of all dialysis patients, those with glomerulonephritis as the cause of end-stage renal disease have the lowest mortality risk and those with diabetic end-stage renal disease the highest mortality risk.1,2 Thus, the survival benefit from transplantation would be expected to have a relatively small impact on the already good outcomes for dialysis patients with glomerulonephritis.
Port FK, Wolfe RA, Mauger EA. Survival After Renal Transplantation-Reply. JAMA. 1994;271(4):269. doi:10.1001/jama.1994.03510280031015