JOURNAL CLUB: Early initiation of dialysis compared to national average

In the recently published IDEAL study, a comparison was made between early versus late initiation of dialysis. Among early start group, 18.6% started dialysis with an estimated GFR of less than 10 ml per minute. And in the late start group, 75.9% started dialysis with an estimated GFR of more than 7 ml per minute. At the time of dialysis initiation, the mean estimated GFR was 12ml per minute in early and 9.8 ml/min in the late start group.

During a median follow up period of 3.59 years, 152 of 404 patients (37.6%) in the early start group died, ie 10.2 events per 100 patient years. ( Mean age 60.2). If we compare this data with national data on ANZDATA:

http://www.anzdata.org.au/anzdata/AnzdataReport/32ndReport/AppendixI.pdf

Australia:
Year Deaths HD %age(Calculated)
2002 1048 7264 14.4
2003 1120 7722 14.5
2004 1208 8007 15.0
2005 1202 8637 13.9
2006 1326 9259 14.3
2007 1459 9701 15.0
2008 1482 10,062 14.7

NEW ZEALAND
Year Deaths HD %age(Calculated)
2002 232 1596 14.5
2003 264 1714 15.4
2004 306 1779 17.2
2005 298 1878 15.8
2006 333 1996 16.6
2007 296 2068 14.3
2008 356 2099 16.9

So as compared to national average, the mortality in the early start group, 10.2 per 100 patient years, appear to be significantly lower. The results are not statistically significant when compared to late start group, which might be because of significant overlap between the timing of initiation of HD, as discussed today.
Any thoughts !!!!!!!!!!
Reference:

http://www.ncbi.nlm.nih.gov/pubmed/20581422