Interesting news from the CMAJ: giving 12-year-old-girls vaccinations against human papilloma virus is likely, on the best existing evidence, to prevent one case of cervical cancer for every 324 doses administered, leaving an implied cost (at about $350 per) of $113,400 per cancer prevented. But wait—that's on the manufacturer-friendly, untested assumption that the vaccine is 95% effective and lasts for life. Assume that the anticancer protection diminishes by 3% per year, and the number needed to treat increases to 9,080—an expenditure of more than $3 million. And the 95% confidence limits stretch out on the long side to infinity, meaning that if the effectiveness of the vaccine diminishes slightly with age, it's possible no cancers will be prevented at all. But don't worry, Merck will probably give us our money back.
Comments (11)
Aren't the HPV strains the vaccine is effective against, also major causes of genital warts? It would seem that this is also a benefit that needs to be accounted for.
Posted by Tybalt | September 10, 2007 8:26 AM
Posted on September 10, 2007 08:26
That's covered in the article, and the NNTs are very much lower. But was the prevention of genital warts part of the rationale for rushed-through public funding of this drug?
Posted by Colby Cosh | September 10, 2007 8:34 AM
Posted on September 10, 2007 08:34
No, but I see quite clearly now that flawed cost-benefit analyses are part of the rationale for decrying it.
Posted by Tybalt | September 10, 2007 9:32 AM
Posted on September 10, 2007 09:32
Sorry, you had a problem with the article or the figures?
Posted by Colby Cosh | September 10, 2007 9:41 AM
Posted on September 10, 2007 09:41
It's funny that there is never talk of vaccinating boys. I assume nearly all of the infected females received HPV from an infected male.
Posted by John Mansfield | September 10, 2007 10:13 AM
Posted on September 10, 2007 10:13
I had no problem with the figures - but you were throwing around "cost per cancer prevented" figures without taking into account the significant other benefits that the vaccine will (hopefully) provide.
It's funny that there is never talk of vaccinating boys. I assume nearly all of the infected females received HPV from an infected male.
As Colby pointed out, without a doubt the whole public debate specifically slanted the vaccine as a gynecological matter, instead of a public health matter generally. This has generally suited both sides that are loudest in the policy debate, since public health is boring but a nice juicy fight over the control of women's bodies is their meat and drink.
Posted by Tybalt | September 10, 2007 11:45 AM
Posted on September 10, 2007 11:45
As always, in my haste I forgot to mention one thing - the vaccine has not been sufficiently tested in men and is still unapproved in men, although apparently there's a growing push to get it approved.
Posted by Tybalt | September 10, 2007 11:49 AM
Posted on September 10, 2007 11:49
That's assuming Merck has any money left after the Vioxx lawsuits.
Posted by Steve Sailer | September 10, 2007 10:24 PM
Posted on September 10, 2007 22:24
Does this vaccination prevent transfers of infections? If so, then it has social benefits beyond the individual benefits.
Posted by Steve Sailer | September 11, 2007 1:22 AM
Posted on September 11, 2007 01:22
It certainly does, but the benefits have little or nothing to do with morbidity, in the case of genital warts, and when it comes to cervical cancer you're talking about an uncertain effect size and a relatively exotic disease. Other interventions (like H. pylori screening) might offer vastly bigger bang for the buck, but they don't have their own jet-propelled bandwagon. Such considerations, to say nothing of the more contentious Viscusian-type analysis, have never entered into the advocacy of the "pro" side and are barely acknowledged even in the "anti" corner. Listening to anybody, you'd never know Canada had any health economists at all.
Posted by Colby Cosh | September 11, 2007 2:04 AM
Posted on September 11, 2007 02:04
the major benefit is that it prevents "precancerous lesions" Since doctors do not know which of these early lesions progress they wind up treating young women with methods that may make conceiving or carrying pregnancy difficult. This is actually a big problem
Boys are not yet vaccinated be cause the risk/benefit to them is different. Studies are now being conducted to check efficacy
Posted by robert schnurr | September 16, 2007 7:24 AM
Posted on September 16, 2007 07:24