Friday, October 13, 2006

Risk assessment

Risk assessment is integral to understanding the issue of homebirth. Obstetricians are generally appalled by the idea of homebirth since they believe it is carries significant risks for the baby, and, to a lesser extent, for the mother as well. Homebirth advocates, on the other hand, are always talking about the puported risks of obstetrical interventions and appear to know little if anything about the risks of childbirth. So in order to get at the truth of the matter, we should take a look at risk, how it is assessed and how it is perceived.

Before we start, I want to make a specific claim. As we look at the various aspects of risk assessment, you will see how they support my claim. This is the claim: Homebirth advocates are, in general, ignorant of the risks of childbirth. Furthermore, they grossly overestimate the "risks" of obstetric technology. These problems are compounded by an inability to understand and evaluate relative risk.

To a certain extent, homebirth advocates are like other Americans in that they do not understand the concept of relative risk and therefore make judgments that are not based on factual evidence. However, I believe that there is an additional cultural factor at work in homebirth advocacy. That is the cultural phenomenon called reflexive doubt. This phenomenon has been identified and discussed in detail by Prof. Craig Thompson. He elaborates on this in an article entitled What Happens to Health Risk Perceptions When Consumers Really Do Question Authority?:
I offer an alternative way of conceptualizing consumer health risk perceptions by using the natural childbirth community as a context that helps us understand how groups of people come to deeply believe in anti-establishment risk norms. This community of reflexive doubt questions whether a hospital is the safest place to labor. Natural childbirth activists believe that low-tech midwifery (preferably in a home setting) provides the best labor outcomes, except for in a small percentage of high risk cases. They also believe that the medical practices of childbirth pose a host of unnecessary and avoidable risks. This community spins an elaborate historical account of how the medicalized birth model gained wide-spread acceptance through a joining of social and political forces and how the model has been established through obstetrical training, hospital practices, and medical technologies.

The natural childbirth community encourages health-care choices, such as midwife attended home births, that are substantially different than the risk norms endorsed by the mainstream medical community. Couples who accept the natural childbirth community's risk perceptions are neither reckless nor relying upon inaccurate decision rules. Rather, they have developed an alternative belief system that comes from an anti-establishment perspective on the risks they attribute to the medicalized birth model. Importantly, their beliefs are far more than an abstract system of thoughts. The natural childbirth model shapes childbirth choices by being accepted as a structure of feeling. These feelings and personal preferences are reinforced through couples' experiences of the medical system and their contrasting encounters with midwives, natural childbirth instructors, and other couples who embrace this alternative construction of risk.

...The risks singled out by the natural birth model express cultural anxieties over the unintended and dehumanizing consequences of technology; the loss of individual independence through the workings of complex 'expert' systems; and a political project of supporting midwifery over the socially-accepted knowledge of the medical establishment. (emphasis added by me)
The concept of reflexive doubt is similar to the idea of defiance that I have spoken about before. If a medical expert says it, the response of the homebirth community is to deny it whether they have any evidence or not. So if a practice is considered safe, homebirth advocates insist that it is dangerous. If a practice is considered dangerous, homebirth advocates reflexively insist that it is safe. Hence the otherwise incomprehensible claims that epidurals pose unacceptable risks while maternal aspiration is a risk that is so small that it should be ignored. Why is this incomprehensible? Because the risk of death from a labor epidural is actually LESS than from maternal aspiration. I would suggest that homebirth advocates literally have no idea that the chances of dying from aspiration are significantly greater than from a labor epidural.

This is the background to a discussion about relative risk. In a future post, I will discuss the actual assessment of risk and how it has been distorted by the cultural imperatives of the homebirth movement.


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