You will find elsewhere in these pages of JASN1 a paper by Argyropoulos et al. entitled “Considerations in the Statistical Analysis of Hemodialysis Patient Survival.” The claim of this work—a comparative statistical analysis—is that the authors have proven their a priori hypothesis that the natural history ofdialysis patients proceeds in an accelerating fashion. As such, they say their chosen statistical method, the accelerated failure time model (AFTM), should be used when evaluating survival on dialysis. The evidence and its interpretation, however, are weak, and both should be considered critically and viewed skeptically. I have several reasons for this view.
Contrary to the authors' assertions, there is widespread agreement that dialysis dose is important to the survival of dialysis patients. The National Cooperative Dialysis Study2 proved many years ago that small molecule–directed dialysis is important. Later analyses using those data, but ignoring length of dialysis (t),3 suggested that a Kt/V of 0.9 was a suitable initial threshold. The Hemodialysis Study4 used higher Kt/V values, but even so, there remains the implication that women had worse survival in the low than the high Kt/V arm.4,5 More to the point, there is widespread transnational agreement that dose is important.5–9 Although some might argue about the best formula for describing dose, opinion converges on a Kt/V ratio of 1.2 to 1.4 per session.6–9
Furthermore, the authors' database is quite small1—only …
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