[It’s the end of the semester here and the rush of obligations has put me a bit behind. I’ll play catch up with a couple of short notes before returning to some more substantial topics.] Here’s a recent story about ART mistakes in the UK. (It’s from the Guardian and there’s more on it from the BBC.)
There are several different ways to think about t. As the headline suggests, the actual number of mistakes nearly doubled between 2007/08 and 2008/09. That’s obviously a dramatic rise. Certainly it suggests we should be concerned. (I’ll return to this in a moment.)
At the same time the actual number of mistakes rose from 182 to 334. That’s 152 more mistakes in 2008/09. I suspect if the headline had said “One Hundred Fifty-Two More Mistakes” it wouldn’t have been nearly so eye-catching.
There’s a third way to look at the statistics What might be most important is the rate of mistakes–by which I mean the frequency of mistakes for a given number of treatments. After all, if the number of treatments quadrupled and the number of mistakes doubled than the rate of mistakes actually fell by half, which would be a positive trend. (To be concrete, if there had been 2 mistakes for 100 treatments (a 2% rate) and now there were 4 mistakes for 400 treatments (a 1% rate), the rate of mistakes would have fallen by 1/2.) Sad to say, I don’t see the comparative rates in the news stories.
That’s probably because the Human Fertilisation and Embryology Authority (the relevant government regulatory) doesn’t provide the information about relative rates of mistakes in their press release responding to the news coverage. (The HFEA hasn’t posted the data for 2008 yet, as far as I can find.) It does, however, say the rate of error is less than 1%.
It’s even possible that the fact that more mistakes are reported does not mean that more mistakes actually occurred. It’s possible that increased oversight lead to the discovery of more mistakes that had previously passed undetected. This is partly the response offered by the HFEA.
By dwelling on the different ways to think about this, I don’t mean to suggest that I think that mistakes are okay. Each mistake made carries its own cost in terms of the people involved. And sometimes the costs are huge.
But it does seem to me that there are different types of mistakes. So, for example, this story seems to say that the mistakes include not having forms properly signed by two doctors. I assume that the requirement of two signatures is itself a safety measure meant to guard against mistakes. Thus, breaching the requirement creates a possibility of further error. But if no further error occurs–if the only mistake is the missing signature–than the harm done seems small. Granted a higher risk of serious harm was incurred, but the feared event did not actually materialize.
Similarly, the loss of sperm (perhaps through improper handling) provided by a man who is able to provide more sperm is a mistake, but one of less than catastrophic proportions. In the grand scheme of things this sort of mistake is not a costly one.
More serious are mistakes that result in the loss of irreplaceable genetic material. Even though I think genetic linkage is over-valued (you can read about that many places on the blog) I can see perfectly well that many other people value genetic linkage highly. Thus, if the last gametes from a person are mistakenly destroyed, something irreplaceable is lost.
Also serious are the instances where samples are switched, so that people end up with the wrong gametes. Even here there are degrees of mistake, though. If the wrong gametes are used but no pregnancy results, it’s a mistake but not one with lasting consequences (unless it also falls into the irreplaceable loss category, above.) Far more serious are the instances where the wrong gametes are used and a pregnancy does result. I’ve written about some of these cases before.
All of this is to say that I don’t quite no what to make of the reported statistics.
But there’s another reason I think it’s worth going through this rather tiresome analysis is that some mistakes, I fear, are inevitable. We are not perfect, nor are any of the systems we can devise. All we can do is strive for the fewest possible mistakes, and the least serious ones as well. And that said, we ought to think, in advance, about how we might deal with the inevitable mistakes, especially the ones that result in the birth of a child.