Monday 13 December 2010

Who pays for these studies?

I'm not in the habit of fisking studies based on the abstract alone, but I'll make an exception in this instance.

Overestimation of Peer Smoking Prevalence Predicts Smoking Initiation among Primary School Students in Hong Kong


To investigate the relationship between perceived prevalence of smoking and smoking initiation among Hong Kong primary second- to fourth-grade-students.


A cohort of 2,171 students was surveyed in 2006 and again in 2008. Students who perceived ever-smoking prevalence in peers as “none” or “some” were considered as correct (reference group), whereas those who perceived it as “half” (overestimation) or “most/all” (gross overestimation) were considered as incorrect.

Hmm. So if they perceived that none of their peers smoked, they were assumed to be correct. That may be true in the sheltered world of tobacco control, but for the rest of us that should be classified as an 'underestimate'. Except there isn't an 'underestimate' option available in this study, which leads me to think that it isn't very well designed.


At baseline, overestimation was found to be cross-sectionally associated with ever-smoking. At follow-up, 7.2% of never-smoking students with incorrect estimation at baseline had started smoking, which was 79% (95% confidence interval: 3%–213%), greater than that of 3.7% for those with correct estimation. Among the never-smoking students with incorrect estimation, subsequent correct estimation was associated with 70% (95% confidence interval: 47%–83%) lower risk of smoking initiation compared with persistent incorrect estimation.

Regardless of whether these kids' estimates are right, it's fair to assume that those who said 'most' had more friends who smoked than the ones who said 'some' or 'none'. And since having friends who smoke is a major predictor of smoking initiation, that—not the overestimating—is the reason they start smoking. The ones who said 'all' would, of course, be liars having a laugh at the researchers' expense. Given that the subjects are schoolchildren I believe, and hope, that there were many of them.


Overestimation of the prevalence of peer smoking predicted smoking initiation among children. Interventions should be carried out to evaluate whether correcting children's overestimation of peer smoking could reduce smoking initiation.

Rubbish. The conclusion is that if your friends smoke, you're more likely to smoke yourself. But I think we knew that already, didn't we?


Michael J. McFadden said...

Now Chris, you really shouldn't be so critical of some poor half-bright bloke who pulled down a few thousand or so for this study. It's no worse than the ones we have here in the States where our traveling Snake Oil Salesmen charge $50,000 to waltz into town, pull out their Magickal Measuring Instruments (tm) and determine that there's more smoke in smoking bars than in nonsmokng bars.

Come on ... if these folks weren't being given money for this stuff, what WOULD they do? They're obviously incapable of doing anything productive. Heh... just take a gander at our "Just a Whiff" Surgeon General!


BrianB said...

Footnote to the IoM study...

In the references at the end of the report; as well as the now obligatory 'hat-tips' to Pell and Gilmore, there are no less than four references to documents authored by Glantz!

I mean, they couldn't make it more obvious, could they?

I need a shower now, innit. The stink of antismoking y'naah. It like sticks to my cloves and my hair and evryfink

BrianB said...

Sorry if the last post seems to be a bit out of context. I had posted a much longer analysis of the Isle of Man heart attack miracle study. This had been visible for over an hour - and I popped in several times to check it - But then it just disappeared. Why?

I would post it again, but I am not in any kind of mood to play stupid games with a crappy piece of software like blogger - which demands (for example) that posts are kept down to 4096 characters, but won't accept anything with more than about 3,800!

I am so f*cked off about this!

Christopher Snowdon said...

Isle of Man article? What? Where? Did anyone else see it?

BrianB said...


email on its way to you (with copy of the study). You on the same email address as 2 years ago I presume?

Brian Bond

Anonymous said...
This comment has been removed by a blog administrator.
Anonymous said...

Yes, I saw BB's post.
I, too, have had the experience of posts disappearing. The posts register. They stay up for 5 to 10 minutes, and then disappear.