One of the most interesting presentations I heard at the recent Fertility Society of Australia conference in Adelaide was not one about cutting edge science or new developments (as an aside, Sydney IVF’s technology is at the forefront of IVF practice but it’s always interesting to get other people’s views and directions). In fact the talk I found the most interesting was from Graeme Hugo, an expert on population, both Australia’s and worldwide.
…this is the title of a song by one of my favourite Australian bands Mental as Anything. This song has nothing to do with statistics (the band members went to Art School), but it’s the launchpad for a discussion of the average of something, or in statistical terms, the mean. To do this I want to make reference to the recently released report by the Austrian Institute of Health and Welfare (AIHW), which annually publishes IVF pregnancy rates for Australia and New Zealand.
Firstly, this data is very valuable. Australasia can be very proud that every IVF cycle and every successful outcome has been recorded (anonymously) in a central database since IVF began 30 years ago. I’ve never, for example, seen national data for the outcomes from naturopathy or detox diets. The data show that we have high pregnancy rates by international standards and we tend to keep problems like multiple pregnancy to a minimum. The good success rates have been maintained over successive years.
However, the results give only the mean percentage rate of all treatments.
For my first blog session aimed at increasing awareness around fertility treatments and in helping you to analyse the myriad of stuff that gets presented out there, I’ve chosen to review a newspaper article that recently came across my desk, written in the Buderim Chronicle. The original article is attached and just like a tutorial, you can use it as background reading for our discussion today.
Welcome to what I call “Pregnancy Rates Analysis 101”. It’s my effort to help lay people better equip themselves with some simple ways of analysing the large amount of noise out there about fertility treatments and getting pregnant, because in amongst the noise, you will be relieved to know that there is useful and accurate information, if you can spot it.
I recently posted some questions to readers about how they might better determine good from bad advice that they either read or receive from friends and practitioners. This section of my blog is dedicated to helping people in this area.
Over the next few weeks I will post a few pieces and in them, take you through some simple strategies and statistical concepts, I hope you enjoy them.
Every week I see couples who are trying to conceive. Prior to seeing me, they have consulted widely as to what strategies supposedly lead to success. There is no shortage of “expertise” out there! Sometimes it’s your know-all friend in the tea room, or a natural therapy person, or a GP, or Doctor Google. I’m always amazed when a particular treatment or strategy is billed as having a “100 percent success rate”. How could anyone believe that?? How can the people that write that stuff expect anyone to believe them? If they were right, no-one would have to do anything else!
Another one of my favorites is “I have seen hundreds of couples over the years and once they took xxxx, they got pregnant.” This kind of statement is generally the basis for segments on popular current affairs TV shows, or articles in popular magazines. But did the potion in question lead to pregnancy, or would it have happened anyway?
So let me ask you some simple (?) questions:
- How do you (or serious researchers) work out whether a particular strategy led to pregnancy, or whether it was a coincidence – that is, it would have happened anyway?
- How would you decide whether an “expert” is really an expert in the area they profess to be?
- How would you define a treatment as “successful” anyway?
HINT: the answers are NOT things like “my friend knew someone who took it, and it worked” or “they were interviewed in the national media, so they must be an expert”.
This question was raised by someone who recently visited the blog. It raises some fundamentally important points about human fertility and the chance of conception. It strikes me that sometimes these concepts aren’t even recognised by some doctors!
The Sydney Morning Herald ran a front page article last week, noting that in the region of 1000 babies were missing (ie not conceived and born) as a result of the Australian Government’s cuts to rebates for IVF patients.