Tag Archives: Mortality

1300

Today’s number brought to you by Funeral Directors of New Zealand.

 

1300

 

Kidney Attack (aka Acute Kidney Injury) is responsible for at least 1300 deaths a year in New Zealand.  It used to be said that people died with Acute Kidney Injury rather than of Acute Kidney Injury.  The paradigm has shifted in the last few years.  Now it is recognised that an acute attack on the kidneys is a killer all by itself.  Of course, the attack is still most often precipitated by another event – heart attack, serious infection, cardiac surgery etc etc etc.

How did I come up with 1300?

A comprehensive study of nearly 20,000 hospital admissions showed that there was a 4.1 times increase in risk of death in hospital for those with Kidney Attack compared to those without.  The Ministry of Health in New Zealand do not report hospital mortality data, but a very helpful MOH information analyst, Chris Lewis (thanks Chris), dug out some numbers for me.  There were 7582 patients out of 548,965 discharges from public hospitals in 2011/12 who were “Discharged Dead”, Died in the emergency department, or Discharged for organ donation.  This does not necessarily capture all deaths (eg Private Hospitals are not included).  However, it gives me enough to go on using the proportion who died overall, the increased odds of death with Kidney Attack (4.1), the estimated number of Kidney Attack patients (30,000), and a little bit of math. The result is at least 1300 Kidney Attack deaths.

 

Deadly ignorance

How many deaths does it take?  We hear that question asked time and again following a tragic event.  We also hear it with calls for changes to our public health priorities.  Well, I am now asking it with respect to Acute Kidney Injury.

  • Acute Kidney Injury (AKI) is one of the most common hospital events (4-5% of patients get it).
  • The most severe forms of AKI result in emergency dialysis.
  • Research out of the US has shown that there has been a doubling of dialysis for AKI over the past decade (1).
  • Now there are 533 cases of dialysis requiring AKI per million people each year in the US.*
  • 24% of those needing dialysis died in hospital
  • About 10 times the number who need dialysis actually get AKI.
  • Even mild AKI raises the risk of in-hospital death and long term kidney problems.
  • More people each year now have dialysis for AKI than those who start dialysis as a result of a chronic kidney disease.

Comparative New Zealand statistics

I would like to do them but have had problems getting funding.  I especially want to look to see if there are any ethnic biases in the numbers.

If we take the US numbers and apply them to our population of 4.4 Million then there would be:

  • 2350 cases of dialysis-requiring AKI of whom 564 would die.
  • Over 20,000 people each year would have AKI.  Many more than 564 would die.

My gut reaction based on the use of dialysis in the Christchurch hospital intensive care unit is that 2350 is probably too high, maybe two to four times too high.  This may reflect differences in dialysis protocols and admittance to ICU.  It is less likely to reflect a lower incidence of AKI.  My best guestimates are:

  • 4000 to 8000 cases of AKI each year with 400 to 800+ deaths.

These numbers are greater than the road toll – another acute event.

They are comparable with Breast Cancer**.

I would like them not to be guestimates.

Maybe the funding will come next year.

The good news

My research and others over the past few years has:

  • identified new biological markers of injury to the kidney
  • assessed many of these and determined that they are of clinical value
  • come up with better ways of defining the disease
  • determined that some pre-existing tools can be applied in slightly different ways to give early warning of changes in kidney function
  • come up with some promising interventions which may reduce the risk of developing AKI

Here endeth the 2012 report.

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1.  Hsu RK, McCulloch CE, Dudley RA, Lo LJ, Hsu C-Y. Temporal Changes in Incidence of Dialysis-Requiring AKI. J Am Soc Nephrol 2012; Online ahead of print.

* the data was expressed in “million-person-years” but as the data was for one year then it is OK to express it as per million people.

**The difference between AKI and many other diseases is that while AKI causes death it is almost always secondary to another event – heart attack, severe infection, cardiac surgery etc, so it is rarely recorded as THE cause of death.