New address for this blog: EP-ology.com

This blog can now be found at EP-ology.com.  I expect this will be the last post at this location.  

The archives will remain here here to preserve existing links (at least as long as Google keeps providing hosting for blogger archives -- and I should say I appreciate the hosting for all these years, but I now use another platform every day, and it is incredibly frustrating switching back and forth).  The archives have also been copied to the new host/location and I suggest that any new links/searches/etc. use those rather than these.  Comments on the archives here are now closed, but are open at the new site.

Random rant about denominator-free statistics

Not particularly relevant to anything, but offering a chance for a random science lesson, I got really annoyed at a couple of items in my twitter feed over the last few minutes.

The first (in which the tweet was ridiculing the claims) linked to this article about a new journal paper which claimed:

Cat bites to the hand are so dangerous, 1 in 3 patients with such wounds had to be hospitalized, a Mayo Clinic study covering three years showed. Two-third of those hospitalized needed surgery.

Regular readers will know my lack of respect for Mayo's attempts at research on anything other than medical treatments. But this is worse than usual. Contrary to the headlines that this claim is designed to generate, obviously only a tiny fraction of cat bites result in hospitalization. Their error, of course, is using "patients" as the denominator, a completely useless population to base the statistic on. Who becomes a "patient"? Obviously it is people who are suffering serious medical problems. In the case of cat bites, this consists of people who, after being bitten by their cat many times before, and suffering no serious problems from it, develop an infection that will not go away. Does this represent 1/1000th of all cat bites? 1/10,000th? Fewer? We have no way of knowing, so the statistic is worthless. More important, we do not know what degree of seriousness typically makes someone a patient. Someone with a non-trivial cat bite injury has no way of guessing her chance of needing hospitalization or surgery because there is no way of knowing how serious the condition of the average patient was in comparison.

(Note: People bitten by stray cats of unknown rabies status might also end up as patients and be hospitalized on spec, which further biases the number away from how it is being interpreted.)

Note that this is exactly the same error that infection disease "experts" always make when there is an exciting disease like bird flu.  They claim things like "half of those who get it die." Um, no. Half of those who get it and get so sick from it that they are willing to go to the almost-certainly-low-quality hospital that they cannot afford (think about the populations in question) end up dying. A bit different.

(If you are particularly interested in that observation, I have written about it at some length in this blog, but I am feeling too lazy to go look for the link.)

The other version of denominator-challenged innumeracy was this tweet from a group calling itself the Center for Priority Based Budgeting, which was naively retweeted by the Robert Wood Johnson Foundation's public health feed.  It included a coded map of the USA and the observation "Half of the nation's uninsured live in just 116 counties".  I am not going to go check this, but eyeballing the map, I would guess that half of the nation's people live in those 116 counties, so this is not exactly exciting news.

Seriously, did everyone who understands numbers from the last couple of generations go to Wall Street, Google, and the NSA, leaving the rest of the world innumerate?

22% of Australian tobacco controlers support genital mutilation

Ok, as you might have guessed, that is not true.  (Presumably.)  But I did get your attention to make the point that they favor something that is equivalent to genital mutilation.  That is not some hyperbolic Godwin-esque comparison.  There really is a pretty exact analogy, even if the harm caused differs quantitatively.

I have been meaning to search my archives for important posts that have not been read as many times as they deserve.  The great tweeter, @TobaccoTacticss -- whose readership has doubled in the last week and a half (you're welcome :-), helped me choose where to start by posting this table from this survey of Australian tobacco controllers.  It shows that 22% expressed support or strong support for "Vaccinating children and/or adolescents against the effects of nicotine to prevent the uptake of tobacco use."

My archive post in question is here, in which I observed:

Most of the discussion about the topic is not about the rational adult making an informed decision, but about involuntarily inflicting the vaccine [a drug that would -- theoretically permanently -- eliminate the body's ability to respond to nicotine] on kids.  Those proposing it tend to gloss over that "involuntary" bit, and failure to even address this is a serious ethical problem in itself.  But, of course, unless we are talking about a current user who is wanting to quit, this is the only interpretation.  Either the kid is already choosing to not use nicotine, in which case he would see no reason to accept the side effects, or he is currently choosing to use nicotine, in which case he would prefer to avoid the vaccine. 

Of course, we take actions that restrict kids' choices all the time.  But there is something rather different when the method involves altering their bodies to make it impossible to enjoy a particular choice (and that choice is not "inflict violence on others" or "commit suicide" or something of that nature).  If the effect were permanent, I think this would be an ethical no-brainer.  I suspect that a permanent effect is the goal of those pursuing research on this vaccine, and inflicting that on someone would clearly be unethical.  No, that is too mild -- it would be utterly appalling.   

Consider the other example (the only other one I can think of) in which adults permanently alter the body of a child to prevent the child from engaging in a behavior that entails some costs, and where they (the adults) do not approve of the kids enjoying the benefits:  the mutilation of girls' genitals practiced in some African communities, which you have no doubt read about.  Before anyone who cannot follow a logical argument flips out, I will point out that I am not claiming that either the damage done or the loss of benefits from the vaccine is as great as that from genital mutilation.  But the motivation and implications are otherwise similar:  enjoyment of sex/nicotine by youth is considered evil by those in power for some reason; the benefits of sex/nicotine result in temptation that can be removed by altering someone's body to diminish the benefits; yes, the behaviors that are thus prevented can increase risks of disease, but this does not appear to be the genuine motivation (e.g., because there are other ways to avoid disease that the proponents oppose).  I suspect that never in my life have I had a conversation with someone who thinks that genital mutilation is anything other than appalling, so why is there no hint of such ethical concern directed at the nicotine vaccine?

Frankly, I think I understated it a bit there because I was writing primarily for a group of young students and not my usual more hardened readers.  It is really pretty much impossible for me to see any ethical distinction between the two practices.  Presumably "vaccinating" children would only be done with the consent of the parents, but that is also true of genital mutilation as I understand.  In both cases, doing whatever it takes to stop the disliked behavior in question is strongly supported in some communities, so no difference there.  They are both about limiting the behavior of the adult that the child will become also.  And so on.  The only tiny bit of light I can see shining between them is the fact that for most (though not all) people the loss of much of the physical pleasure of sex is a larger cost than the loss of the benefits of nicotine -- but that is only a quantitative difference, not a fundamental one.

The survey also found 38% support for "Vaccinating smokers against the effects of nicotine as a cessation method".  This would not be as troubling if this were "making a vaccine available to smokers who wanted it", but it is actually phrased in terms of inflicting the vaccine, not merely providing the option.  Perhaps most respondents interpreted it as the latter.  But if not, it is arguably even worse.  Not only do nearly half support it, but there is no hiding behind "we have to protect the children" because it is trying to deprive adults of free choice by maiming them.  (You can decide for yourself whether this is even worse depending on your personal trade-offs about issues of freedom, children, etc.)

Finally, notice that "as" I emphasized.  Read the original post to see why merely offering a vaccine to interested adults is -- to borrow a favorite phrase of the tobacco controllers -- a wolf in sheep's clothing.  The pitch, like the promise that accompanies the marketing of NRT and other stop smoking methods, would inevitably be that if you take the drug you will not want to smoke.  The reality is that it would permanently (unlike other drugs) trap someone who wants to smoke or otherwise use nicotine in a body that could not use nicotine.

I wish I could take some consolation in the fact that Australia seems to have the most evil tobacco control people in the world.  But I am afraid that the portion of those people who are willing to maim children and adults to control their behavior is not much lower elsewhere.