Accuracy of Drug Study Press Releases

I’m a science gal. I practically drown in the stuff. True, I have a natural curiosity for pretty much everything, but also, I try to keep abreast of what’s happening in the research areas of mood disorders and psychopharmacology. Yes, it’s a lot of work.

I certainly don’t catch everything, but one thing I did catch a while back was this, “Study Finds No Difference In Nonsuicide Mortality Between Two Anti-Psychotic Drugs.”

Basically, neither Zyprexa nor Geodon will kill you more. But is that actually what the study showed?

Geodon and the Heart

When Geodon (an antipsychotic commonly prescribed for bipolar and schizophrenia) went to market it was found that it caused something called QTc elongation. That’s a fancy way of saying it lengthens the time it takes for your heart muscles to do their thing.

[The QT interval is the measure of time between the onset of ventricular depolarization and completion of ventricular repolarization.]

This elongation can lead to heart arrhythmias (irregular heartbeat).

Prior to FDA approval there was no way to prove that this QTc elongation did or did not affect someone’s risk of death. (They say “effects on mortality”. I say dead is dead.)

Study of Geodon vs. Zyprexa

So scientists decided to study Geodon vs. Zyprexa (Zyprexa, another antipsychotic, does not affect the heart in the same way) nonsuicide-related deaths. A perfectly fine thing to do.

They enrolled 18,000 schizophrenics and randomly gave them Geodon or Zyprexa and then measured their nonsuicide-related deaths over the course of the first year of treatment.

Results: there was no difference in nonsuicide-related deaths between the Geodon and Zyprexa groups.

Problems with Geodon vs. Zyprexa Study

What is this study really measuring anyway? Here are the problems from my, unscientific, understanding:

1. There was no placebo group. So Geodon and Zyprexa could both be killing people at the same rate, for different reasons, and we’d never know it because there’s nothing to compare it to.
2. This was an open-label trial, in other words the doctors knew what drug their patient was receiving. This type of study can be rife with bias.
3. This was only one year of study – and the first year of use at that. It’s quite possible that the number of deaths would change dramatically over the course of five years. (Of course, in their defense, long-term studies are very hard to do.)
4. The median age was 41.6 years. That’s quite young for cardiac events. (Another study indicates that patients aged 55-68 with an elongated QTc are at highest risk for sudden cardiac death (8 times more risk than those without an elongated QTc).)

Oh, and in case you were wondering, yes, Pfizer, maker of Geodon, paid for the study.

Geodon vs. Zyprexa – What Does It Mean?

In my opinion? In my unscientific, non-medical opinion? This study means pretty much nothing. Pfizer can put this out in a press release all day long and it means nothing to me. I think there are way too many variables not taken into account for there to be any real conclusions drawn from this data.

FYI, one of the study scientists agrees:

"We could not disprove that the drug caused abnormal heart rhythms, but that was not the goal of the study," says Strom. "Our goal was to determine whether there was a difference in risk of nonsuicide death, and there was not."

Drug Study Headlines Don’t Mean Much

I read this kind of thing all day. I look into studies, here and there, those I find interesting. And what I can tell you is this: if you don’t look at the study details you have no idea what the study actually says. Now, to be fair, the study authors don’t write press release titles, some marketing guy somewhere does. The actual title of the study is:

Comparative Mortality Associated With Ziprasidone and Olanzapine in Real-World Use Among 18,154 Patients With Schizophrenia: The Ziprasidone Observational Study of Cardiac Outcomes (ZODIAC).

Way more boring, but way more accurate.

Rules for Reviewing Drug Studies

So if you’re interested in a study, I recommend:

1. Reading the details carefully, even just the abstract can tell you a lot.
2. Looking up all the words you don’t know.
3. Looking up the original source on PubMed rather than just going by a press release.

And then, after all that, you still might have no idea what they’re talking about. It’s science. It’s pretty complicated. So talk to your doctor. They majored in complicated.

You can find Natasha Tracy on Facebook or @Natasha_Tracy on Twitter.