19 January 2011

Unhealthful News 19 - cost-benefit analyses that ignore the benefits

Cost-benefit analysis (CBA), if you are not familiar, describes a concept and set of methods used in policy analysis to compare – as you might guess – the benefits of a policy (or standard, or recommendation) and the costs.  It is a sensible way to look at things, for obvious reasons, though it has its problems (e.g., sometimes some of the costs or benefits are difficult to put in the same currency as the others).  But it really does not work well at all if you only look at the costs.

The most obvious example right now is the debate over health care financing in the U.S.  There is an argument between those who look at the actual science and conclude that the costs are actually negative (that is, it saves money, so the "cost" side is really a benefit) and the right-wingers who traffic in analytic nonsense to claim that this is not true.  But what is even more astonishing than what the latter group gets away with claiming about the costs is that they get away with ignoring the benefits.  That is, the punditocracy seems to think if they can show that there are net dollar costs then it must be a bad policy.  But, of course, the main benefit of the policy is that far more people get good affordable health care coverage (not me, but lots of people).  Obviously, even if it costs something to bring this about, it might be a good idea.

Another example is the habit of writing about only the costs of nicotine use, which leads to all kinds of absurd conclusions and analyses, as well as a bad outcome in terms of social welfare.  I have written about this many times, and Elaine Keller recently contributed an essay on the topic to our Tobacco Harm Reduction blog.

Lacking an exciting health news story this morning, I fall back on this story from last week, which I had a bit to say about, but was overshadowed by more exciting stuff.  The story involved a move by U.S. regulators to reduce the amount of acetaminophen (Tylenol) in some medicines that include it along with other drugs, such as Vicodin.  The problem is that acetaminophen has an unfortunately low ratio between a seriously harmful dose (in particular, that damages your liver) and the therapeutic dose that you want to take.  Among popular drugs (medicinal or recreational), nothing else has such a low ratio.  That means that accidentally taking more acetaminophen than you think you are taking can be quite dangerous, like when it is the second, less well publicized drug in a drug cocktail medicine and you do not realize you are even taking it, and so take more in some other form also (with "you" being especially older people or others that are being medicated for many conditions).

To try to do something about this problem, regulators have lowered the amount of acetaminophen in cocktail drugs.  Some commentators praised this, as did some news stories (most of which, in a bout of brilliant reporting, just asked the guys who were changing the regulations whether it was a good idea and – surprise! – they praised it).  A very few commentators questioned it.  Not one of them ever looked at the benefit side.  That is, not one commentator – regulator, researcher, or news reporter – ever addressed what the benefit of having acetaminophen-blended drug cocktails is. 

One possible assessment is that there is no benefit:  Acetaminophen is extremely cheap to acquire by itself, so there is no apparent reason for blending it with other drugs.  Instead, a physician who wanted to prescribe something like Vicodin could just say "take one of these (the new formulation of the old medicine, minus the acetaminophen) and at the same time take a 500 mg. acetaminophen pill".  This would allow the additional instruction, "but if you are taking multiple such combinations that include acetaminophen, do not add up the acetaminophen doses! just take it once."  This seems like an excellent solution to the problem that the new regulations are supposed to address.  It solves the problem much better than the halfway solution that is being employed, which is to reduce the doses but still leave the possibility that someone might make the same mistake they are currently making.

The current policy also has the potential problem that the new formulations will contain less than the optimal amount of acetaminophen, so if someone is taking just one of them, they will be underdosing acetaminophen.  Of course, this assumes that the current doses are reasonably close to optimal for the particular drug cocktails.  We might know, had anyone bothered to analyze the benefit side of having acetaminophen blended into these medicines.  If there is some good reason for the cocktails (perhaps there is evidence that people will not take their acetaminophen supplement if instructed as in the above example), and the current doses are right, then presumably the new policy represents some compromise between the best dose for someone who is taking just one cocktail and a limit on the dose for people who are combining multiple cocktails.  But we have no idea about that.  No one had any business praising this as a good policy without looking at the benefit side, and no reporter should have allowed the commentators to dictate the news stories without asking a few simple questions.

If this is a good way to regulate pharmaceuticals, then a good way to regulate cars would be to consider only on the goals of safety and fuel use.  It leads to a pretty silly analysis:  I saw a really cute little car at the toy store that uses no fuel and, barring a Jackass-style stunt involving a steep hill, cannot manage injury-producing speeds.  We would get a rather different recommendation if the regulators worried about such matters as transport (or pain management).

Though in the case of acetaminophen cocktails, I am inclined to believe that actually considering the benefits side would call for greater regulation (which is kind of odd, because usually a failure to consider the benefits side leads to too much regulation rather than too little).  Perhaps I am overlooking something, but I really cannot see any substantial benefit for anyone (other than pharma companies – at the expense of the rest of us – and lazy physicians) of continuing to allow acetaminophen cocktails instead of just telling people to take two pills.  In other words, what was portrayed as a wonderful step forward in solving a health problem was actually an obviously inadequate intervention that was the worst of all worlds, making it more difficult to get the right dosage and still leaving people vulnerable to taking too much acetaminophen without knowing it.  If only the regulators had thought to consider the "B" part of "CBA" we might have had a better policy.  And if any reporter or health policy commentator who wrote about it had thought the situation through and asked about the benefit side, he might have written an insightful story instead of misleading stenography.


[P.S. Helpful note to anyone ever writing a paper that uses a long and impossible to type word like "acetaminophen" quite this many times:  Program a macro or at least put the word in your cut-and-paste clipboard.  I think my brain would have exploded if I had not done that.]

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