One of the true arts learned during renal fellowship is the timing of initiation of dialysis in outpatients with advanced chronic kidney disease. This a crucial skill to develop as the beginning of dialysis has major implications for the patient's lifestyle, finances and well being. In this regard, the publication of the IDEAL trial (reviewed by Matt and one of our top stories of 2010) was a landmark in helping to guide management in these situations, highlighting the safety of waiting for signs and symptoms of advanced chronic kidney disease rather than pursuing early start dialysis solely based on eGFR in closely followed individuals.
Does this differ from what's been going on in practice for the last 10-15 years? A quick look at the USRDS shows that back in 1996 less than 20% of patients started dialysis with an eGFR of greater than 10 ml/min/1.73m2. In stark contrast by 2009 a full 20% were starting with an eGFR of over 15 ml/min/1.73m2 and greater than 50% were starting above the 10 ml/min/1.73m2 mark.
Why the heck did this happen when uremic signs and symptoms, at least in the IDEAL trial, in general seem to occur at GFRs below 10 ml/min/1.73m2?
A variety of explanations have been put forward (well reviewed by Rosansky and colleagues here and here). A commonly proffered argument is that perhaps uremic signs and symptoms are occurring earlier in our aging and increasingly ill population. However, in a study of 2402 nursing home residents who initiated dialysis, the authors found that seven signs and symptoms commonly associated with declining kidney function, such as volume overload and cognitive or functional decline, accounted for less than one third of all cases of early dialysis initiation including less than half of all cases of early outpatient dialysis initiation, suggesting that dialysis initiation may be primarily prompted by laboratory values in a large number of patients.
Regardless of the reasons, the trend is clear, early start was the rule rather than the exception building through the late 90s into the 2000s.
What has this meant for patients and US societal economic cost? A very nice paper from O'Hare and colleagues tells part of the story, using information from a large integrated health care system in Seattle, the group was able to estimate the rate of eGFR decline prior to the onset of dialysis in a subset of patients. This in turn allowed them to predict how many additional days on dialysis patients spent in 2007 versus 1997 by looking at the mean eGFR at time of dialysis initiation in patients listed in the USRDS and then back calculating (this relied on the assumption that the rates of decline were similar in these groups).
These estimates showed that dialysis was initiated on average of five months earlier in 2007 compared to 1997 and almost 8 months earlier in patients over 75! Doing some back of the envelope calculations the group guessed that early initiation in the US had cost an additional $1.5 billion dollars during 2007. This is slightly higher but similar to the over $1 billion dollar additional yearly cost estimate made using slightly different assumptions by the AJKD editorialists for the economic analysis of the IDEAL trial (this was the US estimate - the IDEAL trial was conducted in Australia and New Zealand).
Given that early initiation of dialysis in asymptomatic closely followed patients has no proven benefit (and may even be harmful if you look at recent retrospective data) part of our charge as emerging nephologists is helping to reverse this expensive and unhelpful trend.
(Photo: Stanford Chapel at Night)