I was listening to a radio 4 statistics programme last night, and they made exactly the same point that Ben Goldacre is making here. Namely that all contraceptives have failures and the question is not "How many women using it become pregnant?", but "What percentage of women using it become pregnant?"
As soon as you ask the second question, the contraceptive implant wins hands down.
As soon as you ask the second question, the contraceptive implant wins hands down.