Sunday, May 07, 2006

Birth of a Forum

This forum has its genesis in a post by Neonatal Doc about a baby harmed during a homebirth. The post has generated 160 comments and counting, most about the safety of homebirth. The passions aroused, and the evident enjoyment of the debate by the participants suggested to me the possibility of a forum dedicated to this issue and related mothering issues.

I am happy to host this forum and to offer the opportunity for midwives, doctors and anyone else to post discussion points that people can comment on. If you have an idea for a topic, just send your complete post to me at DrAmy5 at AOL dot com (replace the at with @ and replace dot with a period).

55 Old Comments:

What say you of your colleagues at Homefirst in Chicago? They are among a small population of doctors dotting the United States providing home birth to their clients. Do they also provide care based on blind faith, crossed fingers, and pixie dust as you believe midwives and their clients do? Or as doctors providing home birth are they not even a blip on the radar of risk?

By Blogger MetroMidwife, at 4:37 PM  

Metromidwife:

I visited the link you provided and could find no statistics about their homebirths beyond the C-section rate. I found no statistics about perinatal deaths, maternal deaths or other complications.

I noticed that the medical director appears to have never practiced medicine of any kind. Furthermore, I see no mention of the qualifications of the doctors, midwives and nurses involved. Perhaps you may know where I could find such information.

By Blogger Amy Tuteur, MD, at 4:45 PM  

I was intrigued by the link you provided and this quote:
"What is the purpose of this pregnancy? If it's to have a good experience, skip the pregnancy and go out for dinner and a movie instead. But if it's to have a healthy child, go to a hospital and take advantage of the modern world."
I am interested in evidence-based practice. Research has shown that for low-risk women, homebirth/birth center birth is as safe or safer than a hospital birth. Also, in the U.S. our statistics are pretty bad in terms of perinatal care considering our "modern" technology. A c-section rate of 29%, we rank 25th in infant mortality, and our maternal mortality rate has not improved in 20 years. Countries with the best outcomes use certified midwives for a majority of their birth care. My suggestion to future parents out there - read the research and decide for yourself.

By Blogger jlpetitte, at 6:00 PM  

jlpetitte:

"I am interested in evidence-based practice. Research has shown that for low-risk women, homebirth/birth center birth is as safe or safer than a hospital birth."

Actually, there is no research that shows that homebirth is as safe as hospital birth. That's what the 160 plus posts on Neonatal Doc were about. The three studies quoted most often in support of homebirth, the Farm Study. the Pang study from Washington, and the BMJ study, all show that homebirth has a higher neonatal death rate than hospital birth for low risk women.

You can review the info at the Neonatal Doc post, or we can go over it here.

By Blogger Amy Tuteur, MD, at 8:33 PM  

I'm not sure where you are getting your data from, so I will start with a couple studies here:
1)Birth certificate data from 1991 was examined for all singleton vaginal deliveries between 35 and 43 weeks. After controlling for socio-demographic and medical risk factors, the outcomes for physicians and nurse-midwives were compared:
The risk for neonatal mortality was 33% lower for births attended by CNMs.
The risk of delivering a low birth weight infant was 31% lower for CNM attended births.
The mean birth weight was 37 grams higher for CNM attended births.
The infant mortality rate was 19% lower for CNM attended births.
[Source: MacDorman, M.F. & Singh, G.K. (1998). Midwifery care, social and medical risk factors, and birth outcomes in the US. Journal of Epidemiology and Public Health, 52(5), 310-317]

2)"The National Birth Center Study" reported on the outcomes of care for 11,814 women who were admitted in labor. Results included:
-No maternal mortality.
-Neonatal mortality of 1.3 births/1000; 0.7/1000 if lethal anomalies were excluded. These rates are comparable to studies of low risk in-hospital births.
-Cesarean section rate of 4.4%, approximately one-half that of studies of low risk in-hospital births during the time period studied.
[Source: Rooks, J.P.,et.al. (1989) Outcomes of care in birth centers: The national birth center study. New England Journal of Medicine 312:1804-1811.]

3) In the Netherlands, where 40% of babies are delivered at home, a prospective analysis of 54 midwifery practices and 1,836 women with low risk pregnancies demonstrated that planned home birth was as safe for primiparous women and significantly safer for mulitparous women than planned hospital birth. The authors conclude that "it is important, therefore, that the home birth option remains available, but especially that women at low risk are really given a free choice."
[Source: Wiegers, T., Keirse, M, vander Zee, J, and Berghs, G. (1996). Outcome of planned home and planned hospital births in low risk pregnancies: prospective study in midwifery practices in the Netherlands. British Medical Journal, 7068(313)]

4) "Every study that has compared midwives and obstetricians has found better outcomes for midwives for same-risk patients. In some studies, midwives actually served higher risk populations than the physicians and still obtained lower mortalities and morbidities. The superiority and safety of midwifery for most women no longer needs to be proven. It has been well established." (Madrona, L. & Madrona, M. (1993). The Future of Midwifery in the United States, NAPSAC News, Fall-Winter, p.30"

So, this is just a few of many studies comparing physicians to midwives. You didn't comment at all on our national statistics.

By Blogger Student, at 10:55 PM  

Oh, and I just wanted to add one more thing.

"This forum has its genesis in a post by Neonatal Doc about a baby harmed during a homebirth."
I rotate in a hospital right now and I have seen MANY babies harmed by OBs. In fact, just the other day I saw a baby in the NICU with a huge forcep injury and laceration on the face by an OB.

By Blogger Student, at 11:07 PM  

Student:

The McDorman study is not a study of homebirth; it is a study of certified nurse midwives (it deliberately excludes lay midwives). I worked with CNMs throughout my career and have found them to be excellent. I think we all agree that CNMs are great.

The Rooks study is also not a study of homebirth. It is a study of birth centers. Again, no one is arguing that birth centers are not appropriate for low risk women.

The Madrona piece is not a study, it is an opinion piece in a organization bulletin.

The Weigers study is a study of homebirth in the Netherlands, BUT it does not show that homebirth is as safe as hospital birth.

If you read the study carefully, you will see that it showed a homebirth death rate of 3.5/1000 and compared to a hospital rate of 2.9/1000. The authors hid this very important fact in a "perinatal index" that included over 20 different factors like episiotomy, etc. Only the "perinatal index" of the two groups was equivalent, not the death rate.

In addition the article describes both the hospital and the homebirth group. The statistics from both groups show that the hospital group contained more women who were high risk than than the homebirth group (for example, 15% of the multips in the hospital group were postdates while only 3.9% of the multips in the homebirth group were postdates).

So, I still stand by my claim that the existing evidence consistently shows hospital birth to be safer than homebirth.

"I rotate in a hospital right now and I have seen MANY babies harmed by OBs."

I didn't say hospital birth is perfect. I simply said it is safer than homebirth and by safer I mean that a baby is more likely to die in a homebirth than in a hospital birth.

By Blogger Amy Tuteur, MD, at 11:31 PM  

"The Rooks study is also not a study of homebirth. It is a study of birth centers. Again, no one is arguing that birth centers are not appropriate for low risk women."

I'm curious....what do you think is different about the options and are provided by licensed midwives at homebirths...and CNM attended birth center births?

Both care providers are certified in NNR...both have O2...

both have pitocin..methergine....

What makes you think a birthing center is safer (or frankly - any different) than a homebirth?

In all honesty, Amy...I am not sure what your problem is with homebirths. Everything you're saying isn't the location...it's the care provider. You're questioning the competency of unlicensed midwives. And I have the same problem with OB's...not all OB's are competent.

As for having a homebirth because of the experience...BAH! I had two homebirths BECAUSE, in my case, it was safer. Had nothing to do with the birthing experience..had to do with lowering risks to me and my baby.

I would be curious to know, Amy....if you went into your NICU tomorrow and counted those babies...how many of those babies were homebirthed?

How many babies do you see going into the nicu because they had complications during their elective induction?
How many had complications because the mom's water was broken by the OB?
How many had negative reactions to the pitocin (or Cytotec!) and had to be born via cesarean - and consequently had problems because of the surgery?

I see you pointing to one or two homebirth mismanagements - and saying "Homebirths...that's the evil enemy!" when goodness knows how easy it would be to point to hospitals and infection rates and surgical rates and complication rates and say, "Hospitals...that's the evil enemy!"

As for your question about NICU nurses having homebirths...yes, some of them do. In fact, I've known more than one OB who has had a homebirth. (and many nurses...and many many midwives)

And if I'm blessed to get pregnant again...I will yet again have another homebirth? why? Because it's safer for me and my baby.

By Anonymous Anonymous, at 12:05 AM  

Anonymous:

"I see you pointing to one or two homebirth mismanagements - and saying "Homebirths...that's the evil enemy!" when goodness knows how easy it would be to point to hospitals and infection rates and surgical rates and complication rates and say, "Hospitals...that's the evil enemy!"

No. I am definitely not saying that at all! I am saying that there is no evidence that homebirth is as safe as hospital birth and considerable evidence that a baby is more likely to die at a homebirth than a hospital birth. Partly that is because of care providers; direct entry midwives are simply not adequately qualified. Most important, however, is the fact that the leading causes of death at homebirth (unanticipated serious anomalies, cord accidents, abruptions) are treatable in the hospital, but not at home.

It is axiomatic in the homebirth movement that homebirth is as safe as hospital birth. That simply isn't true. It's not a matter of anecdotes; afterall, I could provide more anecdotes than most since I have delivered thousands of babies. It is a matter of evidence. I am challenging the people who claim that homebirth is safe to provide evidence that the claim is something more than wishful thinking.

By Blogger Amy Tuteur, MD, at 12:16 AM  

Just for curiosity's sake, how many homebirths have you attended Dr. Amy?

By Anonymous Anonymous, at 12:39 AM  

Anonymous:

"Just for curiosity's sake, how many homebirths have you attended Dr. Amy?"

Zero, of course. I would not participate in something that I thought was potentially harmful to baby or mother.

Why do you ask? Are you suggesting that the deaths at homebirths did not happen unless I personally witnessed them?

By Blogger Amy Tuteur, MD, at 7:10 AM  

I've not gone over all the available studies on homebirth in detail, so cannot speak for their validity. I'm surprised that you say that The Farm's outcomes are so poor; I seem to remember reading that their mortality rate was comparable to the national rate, somewhere around 9 or so per 1000, and given the naturalistic and philosophical/religious tendencies I assume that includes babies allowed to die at birth rather than set up in an NICU for weeks or months (and *then* possibly dying but not being counted as perinatal death.)

I *have* looked at the Pang study in detail and don't know how anyone can take it seriously as a proof that homebirth is more dangerous than hospital birth, given the methodological flaws (as the study authors very kindly point out themselves.)

But the problem with allowing stats to guide our choices in the first place is that they don't necessarily apply to individual situations. The woman whose baby died or was damaged due to iatrogenic complications is not going to be much comforted by studies that show that hospital birth is safer than homebirth, and vice versa. There are no guarantees, and no choice that is best in all circumstances, so the best we can do is weigh those circumstances and base the choice on that.

I recognize that there are situations that are best dealt with immediately and with equipment only found in a level III NICU (although I think there is reason to believe that these situations occur only rarely in healthy women with straightforward labors, when labor is not observed and/or managed.) I recognize also that managed birth disturbs the hormonal process, creating a physiologically abnormal birth to some degree or other, and that the hospital environment and/or policies interferes with chemical bonding, and that infection is more likely in a hospital than in one's own home, and that iatrogenic (as opposed to natural) complications are only seen when interventions are employed, and that it is difficult to avoid unnecessary interventions in hospitals.

In my specific case, the latter negatively outweighs the former so heavily that homebirth was more than likely to result in a better outcome for me. Logically, then, that was what I needed to do.

By Blogger Linda, at 3:13 PM  

I always find these discussions rather interesting for awhile, then they go round and round - circular thinking and speaking that finds no outlet for release - even if another blog is made just for the discussion.

I own a book called Evidence-Based Obstetrics (Kames, et al) and it is eye-opening to read the realities of how obstetrics does NOT obey the law of evidenced-based medicine unless it is convenient for them. (The book is at the office, so I won't be offering specific examples, but will if necessary when I grab it tomorrow.)

That a distinction in the book exists that says, "No evidence supporting procedure, but is routinely performed" speaks volumes that statistics are not only manipulated, but also blatantly ignored when it suits the provider.

Why, I wonder, does this on-going discussion about statistics and studies even matter when they are so skewed, so ignored, so dismissed? Why isn't anecdotal experience/evidence accepted when given by midwives or homebirth supporters when anecdotal experience/evidence is given by our medical sisters and brothers and seen as gospel?

Lest I be seen as hypocritical, I often remind homebirth supporters that anecdotal information from doctors, nurses, CNMs and hospitals IS valid and we (collective we) DO need to open our minds and hear what they (you) have to say. Just like we'd like to be heard, so would they.

Closing the absurd books on statistics, what is it we see, do, feel with regards to this topic? How can we change another's point of view if we can't even understand the language they are speaking?

Is changing someone's point of view the goal? (It isn't mine.)

By Blogger Navelgazing Midwife, at 8:03 PM  

"Closing the absurd books on statistics, what is it we see, do, feel with regards to this topic?"

Why should we close the book on statistics? Would you like your heart surgery or brain surgery to be based on anecdotes and personal beliefs? Why should other health issues be any different?

You seem to be expressing a fundamental misunderstanding of what statistics is. The entire point of statistics is to tell the difference between what happens due to cause and affect and what happens due to chance.

I take a medication. I feel better. Should everyone else then go out and take the same medication because it worked for me? Or would they be able to make a more intelligent and informed choice if they knew whether the medication helped a thousand people who took it or ten thousand people who took it?

The math may be daunting, but the purpose of statistics is very simple: to give people accurate information, so they can make good decisions for themselves by themselves.

You also fall into another logical trap: assuming that if some of obstetrics is based on poor data then all of obstetrics is based on poor data. Anything that is not based on good data should be evaluated so we have more information. That's the logical alternative, not relying on someone else's anecdotes.

Finally, you appear to think that if some obstetrical procedures are not evidenced based, that gives midwives the right to completely disregard evidence.

The bottom line is pretty simple. If homebirth is safer than hospital birth, you should be able to show it. Blaming statistics is a desperation move. It's like the carpenter who blames his tools when his woodworking skills are poor. It's just an excuse to avoid looking for the real source of the problem.

By Blogger Amy Tuteur, MD, at 8:24 PM  

Obstetric Myths Versus Research Realities. Both an apropo phrase and a book everyone involved in this subject must read (you too, Dr. Amy).

Dr. Amy ended the conversation at Neonatal Docs by encouraging a poster to send the studies through an epidemiologist or statistician. Guess what -- the WHO already has, and you lost. I don't know why anyone would trust your circular logic (thank you N.M) more than they would the World Health Organization.

For any who have not read it before, from the highest public health expert organization ON THE PLANET:

"From a World Health Organization (WHO) report - subsection on Place of Birth:

It has never been scientifically proven that the hospital is a safer place than home for a woman who has had an uncomplicated pregnancy to have her baby. Studies of planned home births in developed countries with women who have had uncomplicated pregnancies have shown sickness and death rates for mother and baby equal to or better than hospital birth statistics for women with uncomplicated pregnancies."

Given that recommendation, the burden of proof is on YOU, Dr. Amy, not on us. In response to this, you have previously insinuated that the level of safety is different for different organizations. I say this gently, because I hope that I am wrong, but that response tells me that you think American babies are "more special" than Swedish or British or Nepalese or Ugandan or Latvian babies. You didn't really mean that, did you?

By Anonymous maribeth, CNM, at 8:57 PM  

2005 Stats

Here are statistics for "a year in the life of" a midwifery practice. I think it's important for people to see and understand. As you'll see at the end, we offer home, birth center and hospital birth (we have privileges and can manage labor and catch babies in hospital). We serve a 75% Old Order Amish and Mennonite population and therefore have a high incidence of congenital disease (usually lethal).

178 total births in 2005

Antepartum:

10 AP Transfers:

•1 32 week abruption (primary c/s) - well baby.
•1 Planned elective primary c/s - needed other operative procedures at the same time
•4 repeat c/s (all with a history of 2 or more prior surgeries, no trial of labors). We cannot attend women with more than one c/s
•4 2nd trimester intra-uterine fetal demises (2 were delivered in hospital by practice CNMs and other two by collaborative docs). Three had lethal anomalies and one an early cord accident (tight nuchal cord x 3).

Intrapartum: 168 total labors

7 IP Transfers (4%) :

•1 for pit augmentation – SVB by practice midwife in hospital, well baby
•1 for bleeding in early labor – uncomplicated SVB by practice midwife, well baby
•1 breech in labor – primary c/s, well baby
•1 face presentation in labor – primary c/s, well baby
•1 for nonreassuring FHTs (in hospital already, planned hospital birth) – primary c/s, well baby
•2 FTP / CPD – 2 primary c/s, well babies

163 Total Births for CNMs

76 Home births
45 Birth Center births
42 Hospital births

•Total primary c/s n = 5, which is 3%.
•4/4 successful primary VBACs, 100%. Also 3/3 successful non-primary VBACs.
•Post Partum hemorrhage n = 7
•Shoulder dystocia n = 1
•Manual removal of placenta n = 1
•4th degree laceration n = 1

Postpartum:

No PP transfers this year

Newborn:

4 NB Transfers

•All for respiratory distress, three discharged home well at 2-5 days
•One neonatal death at 6 hrs of life for congenital anomalies incompatible with life (EVC dwarfism with hypoplastic lungs and no kidneys)

By Anonymous maribeth, CNM, at 9:10 PM  

Marybeth, I think we have been through this already. This is the opinion of the WHO; it is not a study; it is not evidence.

The WHO is a branch of the UN. Do you find all the decisions of the UN persuasive? Do you think that the UN is an unbiased organization? Great, then get your medical advice from the WHO.

Personally, I don't need an authority figure to tell me what to think. I'd rather read and analyze the evidence myself.

By Blogger Amy Tuteur, MD, at 9:36 PM  

Likewise we've been through a review of valid studies and you continue to shoot them down with the same flawed logic, as if debate never occured, as if your interpretation is expert.

Ok, this feels like beating a dead horse, but honestly, as a professional, you DO NOT consider the recommendation of the World Health Organization? You truly think they base their recommendation on OPINION rather than on evidence? And what supports this supposition Doctor? Can you show me where other physicians feel the WHO is merely based on opinion to accept or not, as is convenient for your end?

By Anonymous maribeth, CNM, at 10:00 PM  

I realize I'm coming across more sternly than intended in my posts. I had hoped not to get carried away by emotion. I do want to continue respectful dialogue. Here's why I lapse: Dr. Amy, us OOH birth advocates spend our lives (and livelihoods) defending our (evidence-based) choice against mainstream medicine. Trust me, we KNOW your argument (and are prepared to counter-attack). As pointed out, that leads to circular debate, us each repeating ourselves but not budging. We are not going to change one anothers' minds. And lets face it, average American moms to be are not reading here.

So let us learn from one another. I may be wrong, and indulge me if I am, but I feel like this is more of an opportunity for you to learn from us than the alternative, merely because we've heard so much of it for so long.

How much contact have you had with OOH birth mothers or midwives? Don't you have questions? Don't you want to know how our great statistics (which setting aside mortality as the only measure you can't deny are better) are achieved? I would love to share some things with you. I would love to ask your opinion on why some outcomes at home are so much better. I think you're now in health policy and I would like to make things better for the industry at large.

As an example, I think a good percentage of primary c/sections could be avoided if OBs had a CLUE about teaching about optimal fetal positioning. Do you realize why so many more OP babies happen these days compared to the past? Can you tell an OP baby prenatally, do you know what a mom should do antenatally and in labor to correct it? I am not trying to demean you, probably you know all this, but see the point I'm trying to make? Let's be productive rather than repeating the same 170 posts from Neonatal Docs...

By Anonymous maribeth, CNM, at 10:14 PM  

Dr. Amy,
What of the CPM2000 study published in the BMJ last year?
It was prospective, evaluated over 5000 women, and showed no statistically significant difference in infant outcomes, yet much less intervention for mothers. It evaluated only homebirth clients working with a Certified Professional Midwife (NOT lay midwives). The CPM is a credentialed midwife whose credentialing organization (NARM) is accredited by NCCA, the same organization that accredits the American Academy of Nurse-Practitioners among others.
see www.noca.org/ncca/accredorg.htm

Some of these CPMs were even working in hostile states where physician collaboration or smooth transports (when needed) were not likely achieved easily. Yet they still got the great outcomes listed in the BMJ.

I've just joined this forum and may have missed something earlier, but am hoping you can explain how a prospective study of over 5000 women does not adquately prove the safety of homebirth.?.

By Anonymous Rachel in Chicago, at 1:33 AM  

One more comment - I noticed your earlier comment about Homefirst. Their medical director, Mayor Eisenstein has been personally attending homebirths for years upon years - at least back into the mid 80's in my memory. You asked where you could get information on Homefirst. The best way is to call them. I encourage you to speak with one of the physicians on staff if you'd like to learn about homebirth from an experienced physician's perspective.

Homefirst even serves as a site for med student internship. I can't imagine this could happen if homebirth was as unsafe as you appear to think it is.

food for thought

By Anonymous Anonymous, at 1:50 AM  

"Actually, there is no research that shows that homebirth is as safe as hospital birth."

You need to read more. How many studies would you like? Start with this recent one. Those of us who birth don't see surgery or interventions without good reason as providing automatic safety and the death rate of caesareans when compared with vaginal births show we're right to feel this way.

Home superior to hospital birth
Source: British Medical Journal 2005; 330: 1416-22

The largest prospective study of planned home births to date evaluates the
safety of such births supported by direct entry midwives.


Among low-risk women, home births assisted by certified midwives achieve
similar rates of intrapartum and neonatal mortality as hospital births, with
lower rates of medical intervention, reveal Canadian researchers.

"Despite a wealth of evidence supporting planned home birth as a safe option
for women with low risk pregnancies, the setting remains controversial in
most high resource settings," note Kenneth Johnson (Public Health Agency of
Canada) and Betty-Anne Daviss (International Federation of Gynecology and
Obstetrics, Ottawa).

To examine its safety further, the team compared perinatal outcomes for all
planned home births (n = 5418) supported by the North American Registry of
Midwives in 2000, with those previously reported for low-risk hospital
births in the USA.

Overall, 12.1 percent of women were transferred to hospital for delivery.
The incidence of neonatal mortality among those who remained at home was
similar to that documented for low-risk hospital births, with no maternal
deaths. Medical intervention, however, was substantially less common among
home, versus hospital, births, with epidural, episiotomy, forceps, vacuum
extraction, and cesarean section rates of 4.7 percent, 2.1 percent, 1.9
percent, 0.6 percent, and 3.7 percent, respectively.

"Our study of certified professional midwives suggests that they achieve
good outcomes among low-risk women without routine use of expensive hospital
interventions," conclude Johnson and Daviss.

By Anonymous Janet Fraser, at 4:32 AM  

Amy, I've only recently embarked on thorough research of the safety of homebirth and I'm already convinced, due to the studies I have come across, that home is indeed safer than hospital. Not only when referring to mortality rates, but also there is less intervention, resulting in less injury for Mother and baby, less trauma, and less PTSD/PND.

Out of time right now, but will return tomorrow with a list of studies supporting this.

By Anonymous Kerrie, at 6:09 AM  

This forum was born from a discussion about homebirth that started on Neonatal Doc and generated over 160 posts.

During that discussion, we analyzed many papers, including 3 in great detail. I will recap some of that below.

I want to make two general claims, first. It is very important to understand that just because a paper appears in a peer review journal, that does not make it true. In fact, that's the entire point of peer review journals. One group presents their findings. Other groups then present findings that either corroborate or contradict the original findings. As a general matter, the truth only becomes apparent over time and multiple studies.

There are plenty of lousy studies. The chief offenders are drug companies that pay for studies to promote their drugs. Often the data in the studies is manipulated to get to the desired outcome. Others can fall into the same trap. Either deliberately, or more often out of an excess of enthusiasm, researchers subtly (or not so subtly) "massage" the data so it says what they want.

That brings me to my second general point. It is necessary to read the actual paper, not the just the abstract. The abstract contains a brief description of the study and the claims of the authors. Only by reading the paper itself can you find out whether the study was done properly, whether the results are statistically significant (exceedingly important) and whether the results actually justify the claims made by the authors.

American doctors are very suspicious, primarily because of their experience with drug companies. So when I criticize a paper, it's not because I disagree with the findings. Often what I am saying is that the results of the study either violate the rules of statistics (which render the results useless)or they make conclusions that are not justified by the results.

What are the red flags that should make you suspicious? In the homebirth studies there are several specific types of red flags. First, the researchers must compare apples to apples. That means that if the homebirth group contains only low risk women with babies in the vertex position, the hospital group MUST contain only low risk women with babies in the vertex position.

Second, researchers are forbidden from excluding bad data. You can't subtract the people with bad results from the homebirth group. They must stay in the group. You certainly cannot subtract people with bad results from the homebirth group and put them in the hospital group, even if they ultimately delivered in the hospital. For example, a woman in the homebirth group who is transferred to the hospital for an abruption and undergoes a C-section after which the baby dies is STILL in the homebirth group.

I'll tackle the BMJ paper in the next post.

By Blogger Amy Tuteur, MD, at 7:11 AM  

Now let's look at the BMJ paper (Johnson and Daviss, 2005). It is one of the three most widely quoted papers in support of homebirth.

This study suffers from serious methodologial issues rendering it problematic:

It is based on self reports by midwives. Would you base a study on the safety of hospital births on self reports by doctors?

Second, when you do the calculations, the actual death rates are:

2.6/1000 singleton births
2.8/1000 twin births
25/1000 breech births!

Moreover, since the authors do not show that any of these deaths were due to anomalies incompatible with life, they leave us with the conclusion that many or all of these babies might have survived in a hospital.

Third, it has a giant red flag in the middle of it:

"after we excluded ... 3 babies with fatal birth defects"

You simply CAN'T exclude the babies who died from fatal birth defects since it is very possible that these babies might have been saved by a neonatologist in the hospital setting. Furthermore, you certainly can't exclude them from the homebirth group if you don't remove the equivalent babies from the hospital group.

Not only is this red flag important because it calls the results of the entire study into question, it raises a serious ethical issue. The authors of the study understand that there are an excess of deaths in the homebirth group, so they simply remove them.

The study also reflects important information about the overall judgment of the midwives. While you and I might agree that only singleton vertex babies can safely be delivered at home, the midwives in this group felt that they could deliver breech babies and twins at home. That tells you that some of them had very poor judgment.

This is one of the best homebirth papers and it still isn't that good. The conclusions are not justified by the data. I can virtually guarantee that any study that includes the words "after we excluded the dead babies from the homebirth group" is a study that has been deliberately manipulated.

By Blogger Amy Tuteur, MD, at 7:40 AM  

Of course, in saying that home birth is as safe as hospital birth, there must be a comparison (low risk hospital) group. And in every one of those studies, lethal congenital anomalies ARE excluded. Amy is making a supposition 'but but but what IF those weren't really lethal anomalies' as if the doctors who attended those babies could not tell. She is taking apples and apples and trying to make them apples and oranges to reach her end. Yet another way she manipulates data to her own end, while claiming that it's actually OTHERS who are doing so. Do check out the debate at NeoDoc everyone to see how it went, lest we have the same frustrating conversation.

The WHO, the Cochrane Review, the American Public Health Association, the state of California, and dozens and dozens of other countries have reviewed the same studies and come to an expert concensus that homebirth is as safe as hospital birth for low-risk women. Trust them or trust a retired OB with an agenda? Hmmmm...

By Anonymous maribeth, CNM, at 11:35 AM  

maribeth, CNM said...
Of course, in saying that home birth is as safe as hospital birth, there must be a comparison (low risk hospital) group.


OK. I think we're finally reaching agreement on this.

And in every one of those studies, lethal congenital anomalies ARE excluded.

This is a problem. Here's why:

If one major risk of home births is that you'll have a death due to undetected anomalies;

If one major benefit of a hospital is that an undetected anomaly can theoretically be treated;

Guess what happens when you "exclude" those from the study?

the study is invalid. Which is to say, it doesn't "prove" what you might think it proves. the real life application is too different from the study.

It's just the same as if I ran a comparison of home births and hospital births, and decided to "exclude" any issues related to anaesthesia or C sections. Hopefully you can see that would be a problem.

Amy is making a supposition 'but but but what IF those weren't really lethal anomalies' as if the doctors who attended those babies could not tell.

Of course they were lethal at home. The doctors did NOT answer the question of whether they were lethal but theoretically TREATABLE.

Dr. Amy is making the (probably correct) assumption that at least SOME of the anomalies were treatable in a hospital. This is a reasonable assumption based on what we know about births in general.

She is taking apples and apples and trying to make them apples and oranges to reach her end. Yet another way she manipulates data to her own end, while claiming that it's actually OTHERS who are doing so.

Um, are you sure it's HER who is doing this?

The WHO, the Cochrane Review, the American Public Health Association, the state of California, and dozens and dozens of other countries have reviewed the same studies and come to an expert concensus that homebirth is as safe as hospital birth for low-risk women.

Sigh. Can you not understand that this is not the same as scientific evidence? The FDA says Plan B isn't safe--do you trust them because it's their job? Or do you know (as do we all) that their "Safety" judgment had nothing to do with scientific fact?

The WHO is a political arm of the U.N. who is tasked with health. However, they are subject to political forces, like the U.N. in general.

The State of California is a political body. I hope that's obvious. So are the decisions of "other countries". Unless, that is, you're prepared to take the stance that "if a government says so, it's correct". I doubt you'd agree with that--and if not, why attribute that sort of expertise to anyone else?

Trust them or trust a retired OB with an agenda? Hmmmm...

Not only is this an ad hominem attack, but it's not even an effective one. You're throwing stones in glass houses.

As a retired MD, Amy has much LESS of a vested interest than any practicing midwife who posts here. Do you plan to discount all your friends because of their "agenda"? Or do you reserve that label for those who you disagree with? In either case, it doesn't make you look good.

By Blogger sailorman, at 12:15 PM  

It is still so preposterous to me that you two don't trust the expert recommendations, and the way you try to rationalize it. Now, if I was saying "The Midwives Alliance of North America" has reviewed the studies and said homebirth is safe, or "ACOG reviewed the studies and said homebirth is unsafe" your arguments would be valid. But I'm not.

Listen guys, I support your right to be against homebirth. But to say it's evidence-based is wrong. You accuse the 'homebirth side' of data twisting but I think it's the pot calling the kettle black. I understand: you think that too. So let's agree to disagree. I am confident in my opinion.

Sailorman, on your final paragraph, you miss the point: these are lethal anomalies. They are excluded from both the hospital and home birth mortality groups. Lethal, untreatable. To say that maybe they were not 'really' lethal anomalies is, you well know, conjecture.

You also again overestimate the value of hospital care. Yes, if you deliver in a hospital with a 24/7 neonatology or peds or anesthesiology team, MAYBE a baby with a diaphragmatic hernia has a better chance of survival than at home -- I don't disagree there. But most hospitals don't. My nearest hospital does not even have a nursery! Babies needing so much as IV lines for glucose are transferred 45 minutes away. Gettting a ped there for a problem takes 45 minutes. The average non-tertiary hospital cannot immediately handle emergencies better than qualified professional midwives can. I'm sure that's shocking to you but it's true. We are NRP qualified. We have oxygen, ambu bags, suction, etc, we have rapid effective transport systems, we can have peds at the hospital in the exact same amount of time as if the baby were hospital born, and support the baby in EXACTLY the same way.

By Anonymous maribeth, CNM, at 9:59 PM  

Maribeth:

"Lethal, untreatable."

No, lethal does not mean untreatable. It means that it killed the baby. If you want to indicate that something is untreatable, you would refer to the anomaly as "incompatible with life." The fact that the authors did not do so when it would have considerably strengthened their argument suggests that the babies died from anomalies that would have been treatable in a hospital setting.

" The average non-tertiary hospital cannot immediately handle emergencies better than qualified professional midwives can. I'm sure that's shocking to you but it's true."

No, I'm not shocked. I'm well aware of the differences between community hospitals and tertiary medical centers. The point is that the studies done to date show a higher perinatal mortality rate in the homebirth group than in comparable low risk populations who delivered in hospitals. That would include community hospitals as well as tertiary medical centers.

By Blogger Amy Tuteur, MD, at 10:15 PM  

I strongly disagree that 'studies done to date show a higher perinatal mortality rate in the homebirth group'.

Interesting you should speak of this, sailorman, as I recently discussed the term incompatible with life with a local MFM doc (perinatologist), who said the term is discouraged from use. I always found the phrase rather odd, as in incompatible with life, otherwise, dead.

We have had three babies die at home since Christmas, all with lethal anomalies identified antenatally, all given the go-ahead for homebirth (and similarly, a peaceful home death) by both our back up OB and our referral MFM group. So you really, truly feel those outcomes reflect some higher danger rate to homebirth and should be included in general stats?

By Anonymous maribeth, CNM, at 11:56 PM  

"So you really, truly feel those outcomes reflect some higher danger rate to homebirth and should be included in general stats?"

The homebirth and hospital groups must be the same in order to create a valid comparison. You can remove these deaths from the homebirth group ONLY if you remove them from the hospital group ALSO.

If there are such deaths in the homebirth population there are likely to be considerably more in the hospital population (since the hospital population is larger). So if you didn't remove such deaths from the hospital group, too, the hospital death rate would be artificially high.

The important thing to understand, Maribeth, is that this is a well known, universally accepted rule of statistics. The authors of the papers know all about it. The fact that they didn't follow it (and therefore lowered the homebirth perinatal death rate so it looked better) is a big red flag.

By Blogger Amy Tuteur, MD, at 6:57 AM  

Maribeth said:
"We have had three babies die at home since Christmas, all with lethal anomalies identified antenatally, all given the go-ahead for homebirth (and similarly, a peaceful home death) by both our back up OB and our referral MFM group. So you really, truly feel those outcomes reflect some higher danger rate to homebirth and should be included in general stats?


Hmm. Let me switch into "teacher mode" and try to explain the statistics better.

Does it reflect a higher danger rate?

No--from what you're describing, those particular deaths appear to be ones which were both lethal in fact, and untreatable in theory.

It would be appropriate to remove from the statistics all cases where an infant was known to be dead or unable to survive with any type of intervention prior to the onset of labor. It would obviously be inappropriate to remove those deaths only from one "side", as I'm sure you can see.

This removal is OK because the death of an infant prior to labor CANNOT POSSIBLY be affected by the place of delivery.

However, this type of data removal doesn't always work. When an infant dies, and you DIDN'T know in advance that there would be a problem, you don't know everything.

You know for sure that the infant died, of course. And you know where the birth took place. But you don't know if the infant would have died had she been born somewhere else.

Thus, it is POSSIBLE that the place of birth was a factor in the death of the infant, and if you're a good researcher, you need to try to figure out the truth.

And how do you test this theory? Well, if there's a difference in deaths between two sites, AND you have controlled for all other factors, it's probably due to one of two things:

Either 1) there was a statistical imbalance, and more "unsavable" babies happened to be delivered at one particular site (e.g. it's not related to the choice of site), or 2) One site has better fetal survivability (e.g. it is related to the choice of site).

The best (only) way to make this determination is to compare deaths between the two groups.


Thus, when the study deliberately excluded the deaths at home, this was improper. Those deaths were not in the category of "things which are guaranteed not to matter". The study needed to include them.

This type of statistica manipulation is particularly improper when the author uses it in support of a point. It's actually sort of OK to make your own data look bad--you're only hurting yourself. But it shockingly inappropriate to make your own data look better. I call it "cheating".

Do you understand the problem now?

I view this as sort of a test. This is a pretty clear issue with the study; I'm talking basis statistics here. If you're not willing to acknowledge the problem, and concede it may be an issue, i'm not sure there's much point in having a dialogue.

By Blogger sailorman, at 9:40 AM  

But you guys keep speaking as if these deaths are NOT removed from the low-risk hospital births studies, and they are.

By Anonymous maribeth, CNM, at 11:04 AM  

No, the problem was that AFAIK the deaths which were excluded were not classified as "absolutely definitely without question unrelated to the site of birth".

It's extremely difficult to make that classification past facto, by examining a dead infant: it only really applies if the infant is known to have died from a problem which has a zero theoretical survivability rate.

You could get away with excluding babies born without a circulatory system, I suppose. But it gets harder fast. And of course, as soon as you start introducing an arbitrary 'this one looks good, this one does not' rule, you're inevitably going to introduce the biases of the researchers. So even if you CAN exclude them it's better practice not to do so.

Anyway, here the exclusion was wrong for statistical reasons. Once the deaths are not conclusively proven to be exceptions it is improper to exclude them from the study.

Read the above post again, starting at the sentence "However, this type of data removal doesn't always work."

This will explain how even though it may "seem" fair to you, it was not appropriate. This is not a value judgment on my part; it's simply bad science.

By Blogger sailorman, at 12:01 PM  

Oh yeah:
maribeth, CNM said...

It is still so preposterous to me that you two don't trust the expert recommendations, and the way you try to rationalize it.


I trust the data, and my own expertise in understanding it. I occasionally trust some panels of experts, whose ONLY job is to provide accurate analysis of data.

I do not, as a whole, trust most governments or organizations (including the WHO) to provide a perfectly accurate summation of the data. They don't have the time, and they have too much bias. Science and politics don't mix well.

You like to attack us on this point, so let me ask you: Are you proposing we believe every panel of "experts" on every topic? Assuming not, what exactly are your criteria for deciding who to believe? Clearly you don't believe Dr. Amy, or any other OB who disagrees with you, though they're certainly "experts" by most people's definition.

Now, if I was saying "The Midwives Alliance of North America" has reviewed the studies and said homebirth is safe, or "ACOG reviewed the studies and said homebirth is unsafe" your arguments would be valid.

Straw man. This is a false dichotomy.

Listen guys, I support your right to be against homebirth.

This is wrong. I am not against home birth per se. I am against misrepresentation of facts in general. If a woman wants to decide to have a home birth, that's her right--and I think Dr. Amy would agree. The only issue here is whether the homebirth advocates, such as yourself, are giving women false information.

But to say it's evidence-based is wrong. You accuse the 'homebirth side' of data twisting but I think it's the pot calling the kettle black. I understand: you think that too. So let's agree to disagree. I am confident in my opinion.

I am not sure how to say this without being insulting. But your comments about the various statistics suggest that what you PERCEIVE as "data twisting" is not. And what you PERCEIVE as "fair" is, in fact, data twisting. This is tricky, as the ability to distinguish took me a while to learn, and requires some training in statistics. And clearly, you're not going to trust anyone who disagrees with you. But in fact, you are wrong.

As for my opinion: I can change it, and often do. Show me the right data and I'll become a great advocate for your position.

I am not so sure about your opinion, however.

Let's say a third person came on here and agreed with our statistical analysis. Would you change your mind?

Look, maribeth, you're "sniping". You don't seem to state a position very often--you just ask for (and get) detailed explanations, and then try to poke a hole in them, or raise a "yeah, but" objection which doesn't address the meat of the matter.

If you think the statistics are so great; if you think you have an accurate method for determining when the WHO or the State of Californis is acting politically vs. acting based purely on science; if you think things have been 'conclusively proven'.... who don't YOU show US what you have to say?

By Blogger sailorman, at 12:25 PM  

Sailorman, are you talking about a particular study that included congenital anomaly deaths for one group and not another? Durand's study of The Farm women included all congenital anomalies in the death rate calculation. (BTW I got a really interesting email from him -- will post it on my blog when I get a chance to finish the post I'm working on.) Johnson & Daviss list the congenital anomalies in the full text version of their paper, in the table following the discussion section.

I agree with you that it's important to report the data accurately. Am working on a more detailed response to your comment on my blog.

By Blogger Jamie, at 3:00 PM  

"Anyway, here the exclusion was wrong for statistical reasons"

Which study specifically are you referencing here?

You are unclear on my position? I do not understand how I haven't shown what I think. Did you READ the posts at NeoDocs?

Obviously, sailorman, we're calling one another on the exact same tactics. Literally, line for line of your critique on me I have given to you and Amy. Would I agree with a third person? Likely not. Would you agree if Marsden Wagner agreed with me? Likely not. Do I close myself off to ever changing my mind if future studies show less favorable outcomes for homebirth? Certainly not.

We are officially going in circles.

I'm still really interested to know your involvement in birth sailorman....?

By Anonymous maribeth, CNM, at 3:44 PM  

For an extremely, extremely, detailed analysis of the Farm study, and why it has an enormous host of problems, see here:

http://moderatelyinsane.blogspot.com/

"Statistics for believers" # 1, 2, and 3.

I would be interested to hear your specific responses to the issues I raise with the Farm study.

By Blogger sailorman, at 5:22 PM  

Jamie:

"BTW I got a really interesting email from [Durand] -- will post it on my blog when I get a chance to finish the post I'm working on."

Would you invite him to come join this discussion?

I am very curious to find out why there was never a follow up study and why the Farm has not made its current mortality statistics public. The Farm Study is quite old and considerable data has been generated in the meantime. Why do they appear to be hiding it?

By Blogger Amy Tuteur, MD, at 7:47 PM  

I would be interested to hear your specific responses to the issues I raise with the Farm study.

Well my first issue is that you changed the subject. I thought we were discussing the exclusion of lethal anomalies from both homebirth and hospital birth groups; specifically, your claim that they are not removed from low-risk hospital mortality statistics. Instead it’s the same debate we’ve already had and that pony is pulp.

From your blog I'll selectively quote parts of it as I go along . One part you forgot to quote from the Farm study was is this one: The NNS/NFMS is a probability sample of births in the United States in 1980 for which a birth or fetal death certificate was filed. Low birth weights (less than 2500 g) and fetal deaths were deliberately oversampled to allow more detailed study of them. Stillborn infants of less than 28 weeks gestational age (or weight of 1000 g) were not included. Of the 16,327 births that ultimately constituted the NNS/NFMS, an additional 2294 were deleted from this study to eliminate those that were attended by non- physicians, those who delivered out- of- hospital, those with no prenatal care, and those in which the mother had prenatal risk factors that were used as exclusion criteria at the Farm.

So your arguments against the Farm outcomes (some of which are valid points) are not counter-balanced by the above. The final statement says that women with previous c/sections were likewise excluded from the hospital data.

But, another concern on that front. You say In fact, many hospitals will not do VBAC, which means that a prior C/S essentially guarantees future operative assistance No, actually, during the years discussed here VBAC was the norm and national VBAC success rates were 70%.

Further, Is there any research suggesting that vegetarian status produces healthier babies? I suspect occupation is actually quite relevant, but I don't have the numbers to prove it

Now, sailorman, this is exactly the kind of statement you accuse others of making without validity. Yet later in your post you infer that of course a vegetarian diet would actually have falsely improved the outcomes again. (For what it’s worth, anecdotally I don’t think vegetarians have better outcomes. In my experience, though I know you discount that, they gain a great deal of weight in pregnancy, with more overall intake in efforts to get enough protein…)

Then there are problems like your statement that Anyone notice the huge difference in education between the two groups? Anyone notice that the Farm population is more educated, by far? I don't have the cites here. But I am certain that education has a positive correlation to fetal and maternal health while neglecting to mention that the Farm women were 1.7 times more likely to have less than a 9th grade education level.

Those are some of my responses. You use the same biases you denigrade others for. We’ve well covered that a ‘perfect’ study can’t be done on this subject, sailorman.

By Anonymous maribeth, CNM, at 10:31 PM  

I'm still really interested to know your involvement in birth sailorman....?

Um, I'm beginning to wonder if maybe you're married to a retired OB? :)

By Anonymous maribeth, CNM, at 10:50 PM  

Maribeth:

This study was done in England, but it may be applicable here, too. It may explain why you keep getting frustrated and keep misinterpreting what I am saying. Note that it was published in a midwifery journal.

Midwifery. 1996 Jun;12(2):73-84.

An exploration of midwives' attitudes to research and perceived barriers to research utilisation.

Meah S, Luker KA, Cullum NA.

FINDINGS: There was a consensus among the midwives that they aspired to deliver research-based care. However, there are clearly a number of barriers preventing this. Research was poorly accessible to most midwives, both in terms of its physical location and complexity. Furthermore, midwives felt they lacked the knowledge and skills to appraise research, and lacked the confidence to judge when research should be implemented. CONCLUSIONS: The current trend to demedicalise childbirth demands that midwives become proficient users of research...

By Blogger Amy Tuteur, MD, at 11:00 PM  

I don't think Dr. Durand will be doing more Farm studies in the near future -- he's in Yap State, Micronesia, writing papers like "Scrub Typhus in the Republic of Palau" and "Childhood Vitamin A Status and the Risk of Otitis Media." It's a long way from Summertown. :-)

I did ask him if he was interested in clearing up some of the questions at Neonatal Doc's -- he sent me a long-ish reply but he didn't join in the fray over there. Like I said up above, I'll post his response on my blog when I get the chance to finish writing the post in my drafts folder.

Sailorman, I don't know much about statistical weighting, but you don't seem to take that into account at all in your critique. There is a brief description of the weighting coefficients in the paper.

By Blogger Jamie, at 11:10 PM  

Dr. Amy, how much epidemiology coursework is typically part of medical training?

By Blogger Jamie, at 11:23 PM  

"Dr. Amy, how much epidemiology coursework is typically part of medical training?"

I had a half year course on statistics and epidemiology in the first year of medical school. It was really boring, but very useful. That was 25 years ago. It may be different now.

I did biomedical research for a year before medical school and that was an enlightening experience. There is so much pressure to publish that researchers often try to manipulate their data. Those researchers were not evil, far from it. They were just so sure that they had discovered something important that they felt justified in manipulating the data to make it look even stronger.

I once actually got into an argument with someone about why we could not use the "great data" from an experiment that had literally fallen on the floor and become contaminated with who knows what bacteria.

That year in the lab left me with a profound appreciation for the tremendous pressure on researchers and the almost irresistable urge to make the data fit the researchers needs.

By Blogger Amy Tuteur, MD, at 11:40 PM  

Thanks, Maribeth, for your specific response. Let me address each individually.

There's a reason I'm not responding to you, btw, on my personal experience. WHat does it matter? I'm either right or I'm not--and my sex, training as a midwife, training as a doctor, or status as a serial killer aren't relevant to that question. Numbers don't have owners.

maribeth, CNM said...

Well my first issue is that you changed the subject. I thought we were discussing the exclusion of lethal anomalies from both homebirth and hospital birth groups; specifically, your claim that they are not removed from low-risk hospital mortality statistics. Instead it’s the same debate we’ve already had and that pony is pulp.


I'm not deliberately being obtuse here, but what pony are you talking about? I mean, the farm study constantly comes up, and it serves as an excellent example of how NOT to exclude data. Are you saying that you acknowledge the Farm study is lacking?

One part you forgot to quote from the Farm study was is this one: The NNS/NFMS is a probability sample of births in the United States in 1980 for which a birth or fetal death certificate was filed. Low birth weights (less than 2500 g) and fetal deaths were deliberately oversampled to allow more detailed study of them. Stillborn infants of less than 28 weeks gestational age (or weight of 1000 g) were not included. Of the 16,327 births that ultimately constituted the NNS/NFMS, an additional 2294 were deleted from this study to eliminate those that were attended by non- physicians, those who delivered out- of- hospital, those with no prenatal care, and those in which the mother had prenatal risk factors that were used as exclusion criteria at the Farm.

Congratulations for finding one of the biggest problems, which I failed to mention.

The issue here is simple: the study tries to show that because they accounted for "factors that were used as exclusion criteria at the Farm", their populations were equivalent.

But they're not.

You need to focus on inclusion criteria, not exclusion criteria. Put another way, it doesn't matter who WASN'T in the two studies--it matters who WAS in the studies.

So your arguments against the Farm outcomes (some of which are valid points) are not counter-balanced by the above.

I'm sorry, but they're not, because you're operating on a faulty assumption that exclusion criteria are the same as inclusion criteria.

The final statement says that women with previous c/sections were likewise excluded from the hospital data.

No, you have misread the study and you are getting this backwards.

Actually, the exclusion criteria for hospitals did not exclude C sections: "Exclusion criteria [for the hospital group] include no prenatal care, out-of-hospital birth, nonphysician attendant, prepregnancy diabetes or hypertension, anemia (hematocrit lower than 28), weight greater than 135 kg, and Rh negative blood with positive antibody screen."

Exclusion criteria for the Farm DID include C sections, for 15 of the ~20 years of the study. In this respect, not even the exclusion criteria matched.

This means that for 15 years, the hospitals had some CS patients, and the Farm had none.

But, another concern on that front. You say In fact, many hospitals will not do VBAC, which means that a prior C/S essentially guarantees future operative assistance No, actually, during the years discussed here VBAC was the norm and national VBAC success rates were 70%.

This is the beauty of a "known" CF. even if this is true, it does nothing to affect my point. Everyone (including you, many times) has agreed that a previous C section can only make matters worse in the future. It never serves as a "benefit" in future births, though it may be neutral.

So, because the hospital group included C sections for fifteen years during which the Farm had none, is is reasonable to conclude the hospitals numbers were artificially low in comparison to the Farm.

Now, sailorman, this [vegetarian and occupation comment] is exactly the kind of statement you accuse others of making without validity. Yet later in your post you infer that of course a vegetarian diet would actually have falsely improved the outcomes again. (For what it’s worth, anecdotally I don’t think vegetarians have better outcomes. In my experience, though I know you discount that, they gain a great deal of weight in pregnancy, with more overall intake in efforts to get enough protein…)

I said I had an unfounded curiosity about vegetarians. I did not base my conclusions on that.

I base my comments on occupation from memory of studies--though I don't have the stats, I am almost certain my memory is correct. If I'm wrong, let me know.

In any case, the overall conclusion is still valid.


Then there are problems like... neglecting to mention that the Farm women were 1.7 times more likely to have less than a 9th grade education level.

Ah, the flipped ratio, where a 2.6% difference (between actual numbers of 6.3% and 3.7%) becomes "1.7 times". This is bad science: the "times" aren't what's relevant here.

(why? Because "times" don't allow you to see ANY difference in actual numbers: it fools you into thinking the effect of a 3% difference in non-h9gh school education ("1.7 times) is the same as the effect of a 15% difference in college education.)

In any case, even if you DO want to use that bad practice, you can't only do that for one number. The study reports in actual percentages everywhere else. If you want to use the "times" measure, then start wincing:

-There were 11 times as many smokers in the hospital group, artificially depressing their numbers. Anyone think this was irrelevant?

-There were 3.8 times as many preemies in the hospital group--anyone want to claim that didn't affect their numbers? Anyone?

-There were 3.6 times as many postdate births in the hospital group.

-The "1.7 times" difference in <9 years of education is an actual difference of less than three percent. Using the "times" is a misleading way to try to obscure that the difference in college education is FIFTEEN percent, in favor of the Farm. Can you really not understand that? I am believing more and more that you're deliberately lying, here.

And so on.

Those are some of my responses.

Thank you. You gave me a better opportunity to explain your errors.

You use the same biases you denigrade others for.

Actually, I don't--not at all. I base my answers on math, not belief. Read my responses above.

We’ve well covered that a ‘perfect’ study can’t be done on this subject, sailorman.

But a much BETTER study could be done. This one is so bad it's actually sort of funny.

I am glad you responded somewhat to my arguments. I'd note that you haven't gone after the main point ('sniping' again?) and I'm curious as to whether you agree. I'm also curious: What would it take to get you to admit this is a bad study?

By Blogger sailorman, at 10:18 AM  

I added a new post to my "statistics" series, on inclusion and exclusion.

See
http://moderatelyinsane.blogspot.com/

By Blogger sailorman, at 12:58 PM  

Can you remind me what is the main point I'm avoiding? Because I also feel like you're avoiding my main point. The pulped pony comment is about debating mortality of home vs. hospital low-risk groups. I was talking about why you insist congenital anomalies were not included in the hospital groups.

If you look over my posts, sailorman, you won't find me quoting the Farm study. I agree that your exception with the gestational age and smoking groups are important. I think there is enough other evidence to support the safety of homebirth.

Even with concession to the GA and smoking issue possibly confounding mortality, I think that comparing the outcomes of 36 week to 42 week healthy low-risk pregnancies (those who would not be risked out of homebirth), outcomes are better.

I also think morbidities are greater in any hospital group and that's an important fact you don't pay attention to. I know you'll ask me to prove it, and I think that's already been done.

By Anonymous maribeth, CNM, at 1:46 PM  

Was that sniping again? I'm getting annoyed by that pejorative and think it unfair. I don't really know what you mean, actually. I'm sorry if you don't like my style. I'm not fond of yours, sailorman, I think it takes a lot of sifting through your post to get your point (math geek you freely admit, and you know it's a stereotype for a reason!). But those points are both quite irrelevant, no?

I'm assuming the problem comes from this: I think the burden of proof lies on your side (and you don't). I feel that most people think homebirth is safe for healthy low-risk women who WANT it. (No one is arguing it's best for everyone). Every doc I know thinks that, actually. I have 15 years in maternal-child health, and know a lot of doctors. As I've bleated on and on, the expert organizations without bias all think that. Anyway, perhaps that's why you percieve that I'm sniping.

By Anonymous maribeth, CNM, at 2:13 PM  

This comment has been removed by a blog administrator.

By Blogger sailorman, at 2:51 PM  

maribeth, CNM said...
If you look over my posts, sailorman, you won't find me quoting the Farm study.


If this is true, I apologize to you. Everyone ELSE seems fixated on the Farm study for some reason. I was sure you went into it in some detail, at least on the neonatal board.

Though to tell the truth, the Farm study is probably worth discussin anyway. It really is a pretty textbook example of a "bad study" and how people rely on things. It's a good teaching tool to those willing to learn. And the difficulty I am having in convincing you of the problems with that study are instructive.

Even with concession to the GA and smoking issue possibly confounding mortality, I think that comparing the outcomes of 36 week to 42 week healthy low-risk pregnancies (those who would not be risked out of homebirth), outcomes are better.

Hmm. The only study we've currently discussed in detail is the Farm study. And the Farm study actually shows the reverse, as I've explained, when you analyze the stats right.

Let's stick to this study for a while, because I really am interested.

I will ask a couple of direct questions to which I would LOVE to get an answer:

1) Do you agree that the Farm population was composed of much lower-risk women than the compared hospital population? If not, why not?

2) Do you agree that the study, as performed, found the home birth and hospital populations to provide equivalent risks?


I also think morbidities are greater in any hospital group and that's an important fact you don't pay attention to. I know you'll ask me to prove it, and I think that's already been done.

I suspect you may be right, though I will refrain from judgment until I see good data. I don't know what's "already been done"; wasn't this in a separate thread here?

Can you give me a full text link to a study? Better yet, can you give me a link, and also analyze the study and explain why you think it is valid? It would save a lot of typing back and forth.

Was that sniping again? I'm getting annoyed by that pejorative and think it unfair. I don't really know what you mean, actually.

Actually, no, it wasn't. Sniping goes like this, and you're really not doing it right now:

I post a lengthy complex argument, which reaches a well supported conclusion, explained in detail.

You (or someone else) seize on a single point which I have failed to explain in detail. This is known as the "yeah but" response. You raise a "counterargument" which is about one line in length, without expressing a detailed alternative. You have posted no details of theories of your OWN, only attacked mine.

I post a lengthy response. This often requires a long explanation again, as the "yeah but" shows a lack of basic knowledge in a certain area.

You then accuse me of being too lengthy.

Repeat as needed.

I'm assuming the problem comes from this: I think the burden of proof lies on your side (and you don't).

Huh? DO you think the burden of proof ALWAYS lies on the side of modern medicine?

What's your standard?

Do you think we need to "disprove" that prayer will heal cancer better than chamo and radiation?

Or are you claiming "special status" for your personal beliefs? A lot of people do this (midwives, creationists, homeopaths, etc) so it's not uncommon, though it's wrong.

I feel that most people think homebirth is safe for healthy low-risk women who WANT it. (No one is arguing it's best for everyone). Every doc I know thinks that, actually. I have 15 years in maternal-child health, and know a lot of doctors. As I've bleated on and on, the expert organizations without bias all think that. Anyway, perhaps that's why you percieve that I'm sniping.

"____ is Safe" is a judgment call, not a statement of fact. It is untestable, and varies depending on your personal stadards of safety.

"___ is AS safe as ___" is a statement of fact. It is completely testable by various means.

We are discussing whether home birth is AS SAFE as hospital birth.

Whether home birth is "safe" or "considered to be safe" is not the same thing. it's not even really rleevant.

By Blogger sailorman, at 2:52 PM  

I was always discussing the BMJ study and the homebirth CNM study in my back and forths with Amy at NeoDocs. I never thought that the Farm study was at the forefront of discussion. Though maybe it was in the early posts, it hasn't been since then.

I don't want to back and forth about the studies, Sailorman. And it's not because I'm afraid my point of view will be proven wrong. It's because I'm busy and want to discuss things that are FUN for me, in my free time (such as some of the subjects in the other threads here). Arguing stats may be fun for math geeks but not me :)

I don't think the burden of proof "ALWAYS lies on the side of modern medicine". Not one bit. I think it lies on the "homebirth is unsafe" camp because I believe homebirth for a healthy, low-risk woman with a professional attendant is an evidence-based practice. Unbiased expert organizations believe it has been proven as safe as hospital birth. I've never met a person, without a bias, who disagrees, actually (that's probably a shock for you). Come to think of it, there's really not even a "homebirth is unsafe" camp. Just you few lone campers. Heck, even ACOG doesn't get involved.

You won't share your bias (and that's your right) but you DO have one. I understand (and agree with) what you said about expert organizations having potential for bias, such as the religious-right-ultra-conservative-Bush-appointed FDA giving thumbs-down to Plan B. But I can’t accept that the organizations I’m referring to meet some 'biased end' by supporting the evidence for homebirth.

I think our fundamental difference comes down to something along these lines… We all know public health is by necessity utilitarian: the good of the many over the good of the few. So of course the American Public Health Association supports homebirth.

Yes, if you are the 1 in 8,000 or whatever women who has an unavoidable cord prolapse, your baby will be more likely to die at home. If you are that woman, homebirth is not ‘safest’ for you. But the other 7,999 healthy low-risk women are safer out-of-hospital, with a professional midwife and a good back-up system. Those women are far less likely to have the risks of c/section, unnecessary interventions, iatrogenic complications and infections, medical malpractice, and so on. As well as, yes, having other bonuses: less pain, more convenience, one on one labor support, facilitation of a family experience, better postpartum follow up, more successful breastfeeding, I could go on and on…

You guys have exclusively been using mortality as the yardstick. And I'm uncomfortable with that. I don't think it's the end all be all, the only measure to use. Lest you say "see, neener-neener, you DO think more babies will die at home", that's NOT what I think at all. But sailorman, for me personally, I can honestly tell you: I would rather have a 1 in 7999 chance of losing my baby than endure the increased risk of mortality or morbidity from iatrogenic complications, endure the total lack of privacy, the dehumanization and the spiritual vacuum of birth in a hospital setting. I understand that you would not accept that risk. I don’t want you to; it’s not right for you.

The evidence for homebirth safety is not about what happens to twins or breeches or babies of <36 week or >42 week gestations – yes, they have higher mortality rates at home, though they’re still pretty small. But for some people, guess what, even that risk is worth it.

I’m not going to argue studies or stats with you, sailorman, but I encourage you to look at the studies of healthy, low-risk women giving birth in hospital. Compare the small chance of a catastrophic OB emergency at home to the risks of more than 28% of women requiring major abdominal surgery and anesthesia, of 15% or so more 'needing' vacuums and forceps, and of in some places up to 50% of 'needing' pitocin -- these things are dangerous when used inappropriately. Plus, the risks of delivering in a location where germs live, of being attended 98% of time in labor by over-worked, sometimes under-experienced nurses, of being a victim of defensive medicine instead of receiving the care that you truly needed, of one thing leading to the next leading to the next leading to all sorts of problems, when most of the time only privacy and patience are really needed. I could go on.

Contrary to your and Amy's opinion, I DO read evidence critically and I DO NOT base practice on my opinion only or on blind faith or in the unwavering belief in all things natural. Most of the time, birth works. Professional midwives are very good at identifying appropriate home birth candidates and identifying when things are no longer normal and further levels of care are needed. There are real risks to hospital birth for normal women.

Sending every woman to an OB in the hospital is like sending every one with a headache to a neurosugeon: it's simply bad public health.

By Anonymous maribeth, CNM, at 9:03 PM  

I mentioned the Farm study just as a counter-example to the claim that homebirth advocates are including congenital anomaly deaths in hospital stats and excluding them from their own. Sorry to confuse things. :-) I have been reading about the literature on homebirth for a while but this conversation has been my first foray into the actual articles. I'm still interested in an opinion on the usefulness of statistical weighting in correcting for the differences between the two groups.

By Blogger Jamie, at 10:09 PM  

...applause...

Maribeth, you said it better than I ever could. Thanks!

By Blogger Cherrie, at 10:10 PM  

Jamie, you should look at the anlysis on my site.

The Farm study had enough major problems that their inclusion/exclusion of congenitals wouldn't have mattered, to tell the truth. Though they do seem to have done some odd things there.

One main thing that seems odd to me about the Farm study is their use of PERINATAL death rate for comparison to the national average.

They list various causes of death at the Farm: (data below copied from Table 5)
Lethal congenital anomalies, 6; Complications related to prematurity, 4; Death in utero before onset of labor, 2; Neonatal sepsis, 1; Abruption (during labor), 1; Respiratory distress, unknown cause, 1; Prolapsed cord, 1; Suspected child abuse, 1; Total: 17.

Out of those, the vast majority seem like neonatal deaths to me. Don't they look like neonatals to you? What is an abruption, or a lethal congenital anomaly, or an in-utero death, doing in the perinatal rate?

You need to find a motive. If the Farm's deaths were actually neonatal deaths and not perinatal deaths, why compare the Farm numbers to a national PERInatal death rate, instead of a national NEOnatal death rate?

One reason which springs to mind (given the various other issues in the study): Because the perinatal death rate will be higher, and the Farm numbers "look" better as a result.

Surprise!

Even without the number-crunching-to-look-good stuff, this is doubly odd because the study is looking at BIRTH SITE differences. Perinatal numbers reflect a combination of birth site, post-birth care and feeding, etc etc.

In other words, using perinatal numbers introduces another 100 "confounding factors" which make it almost impossible to draw accurate conclusions about the effect of birth site on mortality. If you're going to try to look at perinatal rate, you need to use a lot more controls, and youneed populations which match much better than these did.

By Blogger sailorman, at 9:29 AM