Tuesday, December 05, 2006

Smear tactics

Smear tactics are a staple of modern politics, but they can be used in other areas as well. Henci Goer's recent article is an excellent example of classic smear tactics in action.

Smear tactics work by manipulating emotions. They DEPEND on the assumption that most people have neither the time nor the knowledge base to evaluate whether the smear is factually true. They DEPEND on the assumption that if you deliberately associate a person with a bad event, most people will have neither the time nor the knowledge base to evaluate whether that particular person was in any way associated with the bad event. They DEPEND on the assumption that if you "throw enough mud against the wall, some of it will stick".

The following paragraph is an excellent example of the fine art of the smear:
Gawande applauds doctors for trying whatever appeals to them without “wait[ing] for research trials to tell them if it was all right.” It is sufficient that obstetric innovators “looked to see if results improved,” although how they would know this without a controlled evaluation of safety and effectiveness, he does not say. Neither does he bring up the obstetric disasters that have followed in the wake of this approach. DES, thalidomide, retrolental fibroplasia (blindness in premature newborns), and misoprostol (Cytotec) inductions come to mind ...
Let's do what we're NOT supposed to do, let's analyze this sentence for factual accuracy to find out whether obstetricians really created these problems, and created them because they did not take the time to do controlled trials before instituting a new practice. Here's what we need to know: what do the terms mean? when did these events occur? were obstetricians responsible for promoting these practices? did obstetricians institute these practices without appropriate controlled trials?

I'll start with the easy ones first and save the hard one for last.

thalidomide

What is thalidomide? Thalidomide is a medication was used in Europe during the early 1960's. It was prescribed as a sedative. Thalidomide taken in the early weeks of pregnancy causes limb defects. Typically, the babies were born with flipper like appendages instead of fully developed arms.

When was thalidomide used? It was used in the early 1960's. No medications causing birth defects had ever been identified before. No one knew it could happen.

Was thalidomide use promoted by obstetricians? No. Furthermore, thalidomide was never used in the US. An official in the Food and Drug Administration refused to allow the drug to be used in the US because she had read the case reports in the European literature. As a result of the European experience, the FDA instituted studies to see if other medications could cause birth defects.

Bottom line: Thalidomide was never used by obstetricians and was never even allowed in this country.

Retrolental fibroplasia

What is retrolental fibroplasia? One of the leading causes of death of premature babies has always been immaturity of the lungs. Since they don't work properly, the baby cannot get enough oxygen from room air. Initially, this was treated with oxygen piped into incubators.

When did this occur? Oxygen supplementation for prematurity was instituted in the 1940's. Thousand of lives were saved by it. The side effect of blindness was noted almost immediately thereafter in the survivors. The hunt for the cause was on. It was not until the early 1950's that it was recognized that the cause was high concentrations of oxygen.

Did obstetricians use it? No, it was used by pediatricians to save premature babies.

Were controlled trials done? No, no one thought it was necessary to test oxygen before using it on premature babies.

Bottom line: Retrolental fibroplasia has nothing to do with obstetricians. I find it very difficult to blame pediatricians for this unexpected side effect, but if Henci Goer wants to do so, she can.

Cytotec

What is Cytotec? Cytotec is a prostaglandin. Since prostaglandins are known to stimulate readiness of the cervix for labor, it was used as part of inductions.

When did it happen? It has been used for the past 15 years or so.

Did obstetricians use it? Yes.

Were controlled trials done? Yes, they were. Studies showed Cytotec to be safe and effective. It wasn't until the drug was put into clinical practice that the affect of Cytotec on women with previous uterine incisions was noted. Those women were more likely to rupture the incision than women who didn't receive Cytotec. The same people who published the original studies showing the safety of Cytotec were the ones to publish the studies showing it wasn't safe for women with previous incisions.

Bottom line: Cytotec went through the process that Goer recommends and was found to be safe. It was only during widespread use that the side effect for a subgroup of women was found. The system worked exactly as Goer insists that it should work.

DES

What is it? It is a hormone that was thought to prevent miscarriages.

When was it used? From 1938-1971.

Did obstetricians use it? Yes.

Were clinical trials done? Trials were not done until the early 1950's and they showed the DES did not prevent miscarriages. Some obstetricians continued to prescribe it anyway because they wanted to be able to show women they were doing something to prevent threatened miscarriages. The FDA told physicians to stop prescribing it in 1971 after it became apparent that DES caused rare vaginal cancers in adult women who had been exposed to DES in utero.

Bottom line: DES was never shown to be effective in preventing miscarriage and should not have been used. No one anticipated that it could cause defects that wouldn't show up until adulthood; this was the first time that a defect was not noted until adulthood.

So, of the four side effects that Goer writes about in this sentence, two had nothing to do with obstetricians at all, and one was handled in exactly the way that Goer prescribes. Only DES stands as an object lesson in why new treatments must be tested before allowed into clinical practice.

There is one more component to the smear that must be addressed. DES has not been used for 35 years. Very few if any practicing obstetricians have ever prescribed it. Nontheless, Goer implies the following claim: if the predecessors of today's obstetricians were wrong, you cannot trust anything they say today.

In politics, smear tactics tell us more about the person who uses them, then about the person accused. It is the same thing here. Goer is so desperate to condemn obstetricians that she throws any "mud" that is available, whether it is true or not, hoping that some of it will stick. A smear is not an argument, though. It is merely a sign that her own argument is so weak that she needs disreputable tactics to bolster it.

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