Thursday, May 25, 2006

Dr. Durand and the Farm study

Several weeks ago, Jamie mentioned that she had corresponded with Dr. Durand, the author of the Farm study. I asked her to invite him to participate in this discussion, but she felt that he would not be interested given his other substantial time commitments. She promised to share what she learned from him, and now she has. She has reprinted (with his permission) a lovely letter on her website.

I was disappointed to see that there was no specific defense against the criticisms that have been raised against the Farm study. Here is the relevant passage:

Dr Tuteur is mistaken in her reading of the Farm paper- even after controlling for the differences in race between the Farm and comparison (National Natality Survey) populations, the infant mortality rate was actually less in the Farm group, though not significantly so by statistical testing (and since the statistical tests fail to show a significant difference we cannot say with confidence that either group had better results for this outcome measure).
Unfortunately, there is no explanation for the statistical problems with the study including failure to quote the actual neonatal death rate from the homebirth group and the use of NNS/NFMS group as the control group Essentially, Dr. Durand compared the results at the Farm with the results of all American deliveries, including all races, all gestational ages and all medical complications, except those specifically excluded at the Farm. Most importantly, Dr. Durand does not acknowledge that there is actual data about the true neonatal mortality rates of low risk white women at term from the time period, and they are very substantially lower than the neonatal mortality rate from the Farm.


10 Old Comments:

again what group would you match control with? a group that had that many breeches and twins in it with 20% black population- also women with other problems( I have said it before and continue to say it they take women who will not get a vaginal delivery or attempt else where-- even in recent years) so this is not truly a low risk population.
if you read the Farm book you see what all has gone on there and you can be clear about what happened when. There is no hiding the info

By Anonymous Anonymous, at 10:07 AM  

You need to match the Farm group with low risk white women at term.

At the time they did the study, the midwives at the Farm thought and said that breech and twins WERE low risk. It turns out that they were wrong about that. That doesn't mean that they get to subract those mistakes from the poor outcomes.

Most importantly, the neonatal mortality rates for a comparable group of low risk white women was probably significantly less then 4/1000 at that time considering that the overall neonatal mortality was 7.4/1000 and over 50% of neonatal deaths are due to prematurity. Therefore, the Farm had a neonatal death rate that was more than 100% greater than the hospital group.

This is extremely important because there were many sets of figures available to Dr. Durand, but he chose to compare the Farm Group to a group that encompassed virtually all pregnant women in the US regardless of race and included a tremendous number of pregnancy complications.

The Farm numbers were very poor and they were trying to obscure that fact.

By Blogger Amy Tuteur, MD, at 11:10 AM  

Durand included all deaths: antepartum, intrapartum, and neonatal, including those resulting from lethal congenital anomalies (6/17). The Farm midwives serve not only Farm residents but also nearby Amish women, which may be a factor in the rate of lethal anomaly deaths.

To make an accurate comparison, we'd need to know how the deaths were distributed (since mortality stats declined btw 1971 and 1989) and we'd need to compare them to numbers for antepartum plus intrapartum plus neonatal mortality, not neonatal mortality alone.

By Blogger Jamie, at 11:12 AM  

Any chance we could get Durand to respond to the specific issues?

As should be obvious to anyone who read the study, race is ONE of the factors, but by no means the ONLY factor, in which the Farm population differed from controls.

And, of course, there are the questions to ask about HOW he "controlled" for race, and the statistical stuff.

It would be so, so, so, very nice to actually get Durand to talk about this. Because who knows? Maybe the study actually DID who home birth was safer or as safe.

By Blogger sailorman, at 11:15 AM  

Email him, Sailorman!

By Blogger Jamie, at 11:16 AM  

What's his email?

By Blogger sailorman, at 1:54 PM  

If you don't want to post his email here (for obvious reasons) you could email it directly to me (see my blog).

If you are already in contact with him, this is my email. You could simply forward it on my behalf:

Dr. Durand,

I have read your Farm study with much interest. As is common for me after I read a study, I have some questions about the methods and conclusions which I would love to discuss with you. I have read your response to Jamie, and though it is interesting it doesn't really address my own questions.

If you would be willing to discuss the issues by private mail, I would be much obliged. If you would be willing to discuss them AND to have me post our conversation (unedited) online for others to read it, I would be doubly obliged.

Please let me know.

By Blogger sailorman, at 2:46 PM  

Sailorman, I already wrote to ask if he'd mind my sharing his email address. If I don't hear back shortly, I'll send him your message.

I'm not ignoring your response to me a few posts below -- back to you soon, 'kay?

By Blogger Jamie, at 3:14 PM  

Amy, would you be willing to edit the text of this post to remove the inaccurate statement that Durand excluded congenital anomaly deaths? I would appreciate it.

By Blogger Jamie, at 12:30 AM  

Done, Jamie. I apologize for that mistake. The studies are starting to blend together in my mind.

By Blogger Amy Tuteur, MD, at 7:23 AM