Friday, August 15, 2008

Who practices evidence based medicine, doctors or DEMs?

Homebirth advocates are fond of claiming that obstetricians do not practice evidence based medicine. That could be a devastating critique, if it were true, so let's investigate whether it is true.

"Evidence based medicine" (EBM) is a specific philosophy of medical care. A 1995 editorial in the British Medical Journal announcing the creation of the journal Evidence-Based Medicine gave this definition of EBM:
... evidence based medicine is rooted in five linked ideas: firstly, clinical decisions should be based on the best available scientific evidence; secondly, the clinical problem - rather than habits or protocols - should determine the type of evidence to be sought; thirdly, identifying the best evidence means using epidemiological and biostatistical ways of thinking; fourthly, conclusions derived from identifying and critically appraising evidence are useful only if put into action in managing patients or making health care decisions; and, finally, performance should be constantly evaluated.
Let's analyze each component individually and determine how closely obstetrics and direct entry midwifery (homebirth midwifery) adhere to each.

1. Clinical decisions should be based on the best available scientific evidence: Notice that the requirement is NOT perfect evidence, simply the best available evidence at the time.

Does obstetrics adhere to this model? Yes, it does. Obstetricians are constantly gathering evidence, testing hypotheses, and using the evidence gathered by themselves and other doctors and scientists to formulate treatment algorithms. Old evidence is constantly being replaced by new and better evidence. Treatment decisions change in response to the new evidence. How important is the role of scientific evidence in obstetrics? It is so important that every obstetrician is expected to follow the scientific literature on a monthly basis. In addition to scientific journals that report the latest studies and evidence, there are journals devoted solely to instructed obstetricians on how to incorporate the latest evidence into clinical practice.

Is direct entry midwifery based on the best available scientific evidence? No. In fact, it is not based on scientific evidence at all. DEMs do no research, test no hypotheses and have no treatment algorithms. There is no scientific evidence in support of virtually any practice exclusive to direct entry midwifery.

2. The clinical problem - rather than habits or protocols - should determine the type of evidence to be sought. Obstetricians base their practice on identifying the clinical problem and treating it. DEMs do not even acknowledge the existence of many clinical problems, and have no experience in the diagnosis and management of clinical problems. Of course, they don't even bother to seek out evidence on treatment.

3. Identifying the best evidence means using epidemiological and biostatistical ways of thinking: Once again, obstetrics meets the criterion, but direct entry midwifery doesn't even bother to try. Moreover, direct entry midwifery is actually opposed to this philosophical principle of evidence based medicine. Hence the reliance on intuition, tradition, and "other ways of knowing", all of which are fancy names for ignorance.

4. Conclusions derived from identifying and critically appraising evidence are useful only if put into action in managing patients or making health care decisions: In other words, there should be timely incorporation of new evidence into clinical practice. Obstetrics follows this criterion, although there are times when it could do even better. Not every obstetrician incorporates new evidence as quickly as he should. Of course, direct entry midwifery doesn't bother gathering new evidence, let alone incorporating it into practice in a timely fashion.

5. Performance should be constantly evaluated: Once again, while obstetrics tries to adhere to this criterion, obstetricians could do better. The Federal and state government collect statistics on every aspect of obstetric care, analyze them, and make them publicly available for free every year. Recent initiatives have upgraded evidence collection in areas of particular concern, such as maternal mortality. In contrast, direct entry midwifery has made evidence collection voluntary, hides its own statistics, and is publicly dishonest about the safety of its practices.

So how do obstetrics and direct entry midwifery compare in their adherence to evidence based medicine? If I were grading, I would give obstetrics an 85%. There is considerable room for improvement particularly in implementing the latest clinical recommendations, and in collecting statistics. In my judgment, the greatest deficiency of obstetrics in the realm of EBM is the failure to provide the public with universal statistics on every hospital and every doctor.

On the other hand, direct entry midwifery gets a 0%. There is no effort, not even lip service, paid to any principle of evidence based medicine. Not only does direct entry midwifery fail to comply with the principles and practices of EBM, it is actually philosophically opposed to many of the basic goals of EBM. There is no place in EBM for "intuition", tradition, or "other ways of knowing". There is no place in EBM for "trusting" birth.

When it comes to evidence based medicine, direct entry midwifery is a complete and utter failure.

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