Does emergency hospital choice matter?
The Herald has a completely over-the-top presentation of what might be an important issue. The headline is “Hospital choice key to kids’ survival”, and the story starts off
Where ambulances take badly injured children first seems to affect their chances, paediatric surgeons say.
Starship children’s hospital surgeons have found that sending badly injured children to the wrong hospital may be contributing to a child death rate from injuries that is twice the rate of Australia’s.
The data:
Six (7 per cent) of the 88 children who went first to Middlemore died, but so did one (8 per cent) of the 12 who went directly to Starship.
That is, to the extent the data tell us anything, the evidence is against the headline. Of course, the uncertainties are huge: a 95% confidence interval for the relative odds of dying after being sent to Middlemore goes from a 40-fold decrease to a 12-fold increase. There’s basically no information in the survival data.
So, how much of the two-fold higher rate of death in NZ compared to Australia could reasonably be explained by suboptimal hospital choice? One of the surgeons involved in the study says
… overseas research showed that a good trauma protocol system could cut the death rate for injured adults by 20 to 30 per cent, but there was no good data for children.
That is, hardly any of the difference between NZ and Australia — especially as this specific hospital-choice issue only applies to one sector of one city in New Zealand, with less than 10% of the national population.
On the other hand, we see
The head of Starship’s emergency department, Dr Mike Shepherd, said the major factors contributing to New Zealand’s high fatal injury rate for children lay outside the hospital system in policies such as driver blood-alcohol limits, graduated driver licensing, and laws requiring children’s booster seats and swimming pool fences.
That sounds plausible, but if it’s the whole story you would expect high levels of non-fatal as well as fatal injuries. The overall rate of hospitalisations for injuries in children 0-14 years is almost identical in NZ (1395 per 100 000 per year, p29) and Australia (‘about’ 1500 per 100 000 per year, page v).
Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »
And this too from the article: «Statistics NZ figures … 11.1 deaths for every 100,000 children aged under 15. There was only a slight downward trend from a death rate of 11.2 a year in the first half of the decade to 10.7 in the second half.»
That smells like “picking your sampling range”; is that decline really supported by the evidence?
11 years ago
“There’s basically no information in the survival data.”
I just had to calculate the information content of the data. With a uniform prior on the two proportions (silly given the context), the information gained is 4.763 bits. That’s quite a lot! With a better prior (hospitals probably similar to first order) and a better question (what’s the difference between the two) the information would surely be much less.
11 years ago