Happy new year to everyone!
I don’t normally mention TV news here, but they can slip up too. Channel 4 News yesterday ran a big, scaremongering piece about one simple statistic: 584 people with contraceptive implants became pregnant.
This might be newsworthy, except Channel 4 forgot to mention two rather important things, subsequently picked up on by the BBC.
First of all, the data in question covers 11 years, not just one year.
Secondly, over that time, the implant has been used by around 1.4 million women.
Now fair enough, presumably not everyone who got pregnant after using Implanon reported it, and contraceptive failure is always regrettable. 584 pregnancies among 1.4 million users however means that the implant did not fail in 99.95% of patients. That is very, very reliable in medical terms.
For comparison, vasectomy is 99.9% effective, an IUD is 99.8% effective, the pill is 99.7% effective (when taken properly; people missing doses means that in real life, it’s only 92% effective on average) and condoms are 98% effective (again, when used properly).
It’s always good to make sure people are completely aware of the relative risks of any type of contraceptive (and indeed any medicine), but using these 584 pregnancies as a sign that there’s something wrong with the implant, without any kind of context or an explanation, isn’t going to do this. All it will do is scare people – as Channel 4 have now realised. They’ve since released another article, “Implanon implant: what to do if you’re worried“, which explains:
You do not need to speak to your doctor unless you are very worried and need to have your mind put at rest.
As long as you can feel the implant, there is no cause for concern. The implant is still a very popular, safe and reliable method of contraception.
No method is 100 per cent effective but only a tiny number of women using the implant have got pregnant.
Good advice, but they should have put that in the actual article yesterday.
#1 by Bob on Wednesday, 5th January 2011 - 18:43 GMT+0100
All the media are woeful at using statistics accurately. I saw the report you mentioned and questioned the lack of context at the time. Thank you for providing it.
It’s not complicated. Journalists should be required to read “How To Lie With Statistics” by Darrell Huff.