Saturday, 27 October 2007

Melanie Phillips: part 2

One of the (few) specific claims Melanie Phillips made about drugs on the Moral Maze was that "75% of parents who kill their children are cocaine users". Now, apart from what I call the "Ribena effect" (their advertising claims that 98% of British blackberries are used to make Ribena in a way that implies that Ribena is 98% blackberries. It's not), there are so many qualifiers that you'd need to add to this statement to make it meaningful:

1. Just how many parents have killed their children in the UK in the last, ooh, 50 years? If it's less than about 1000, then I'd say that you'd need to put some pretty big confidence intervals around your 75% claim.
2. What proportion of cocaine users who are parents kill their children? If it's <0.1%, I imagine that it's starting to look comparable to rock climbing, road accidents, etc in terms of risk.
3. Does the number of parents killing their children over the last fifty years correlate with cocaine usage over the last fifty years?
4. Is it a particular kind of cocaine? Crack?
5. Is it a particular kind of user? An addict taking *much per week?

I realize that I shouldn't get so angry over someone who is so obviously an idiot. But she seems to embody everything that's wrong with the popular press that it's hard not to be angry that she gets to express her views in print to hundreds of thousands (millions?) of readers and attempt to sway them. Bah.


Paul Walter said...

Yes, it's funny how it is a tidy 75%. It would be interesting to hear from where she gets this statistic.

It seems it may have originated in a report from the Journal of the Royal Society of Medicine here:

But I can only find two separate references:

"In a study of mothers who
had committed infant homicide, most reported regular use
of alcohol and/or cocaine antenatally and postnatally."


"Resnick2 reported that 75% of parents who killed their children had psychiatric symptoms shortly before committing the act."

It seems that Phillips has conflated these two statements and also conveniently ignored the fact that alchohol was mentioned as responsible for those cases in the study, as well as cocaine use.

john b said...

That's an interesting paper. It also suggests 45 infant homicides (including neotaticides) per year - so given that 3% of the population are cocaine users (here), even if the 75% stat were true then the risk that taking cocaine will make you murder your baby would still be neligibly low...

Mark Wadsworth said...

I thought it was more like 50 - 100 children murdered by parents in the UK per year, that what it says here at least.

So even all infanticides were coke-induced, and assuming John B's 3% figure is correct, only 0.04% of coke users murder a child every year.

Trooper Thompson said...

Whenever I see a case of a mother murdering her child or children, my question is 'was she on prozac, or another anti-depressant or anti-psychotic drug?' because I believe these prescription drugs are linked to a lot of such crimes.