It seems lately that questions of medical ethics are coming up more and more in the news, things like the rights of patients to make decisions, definitions of futile care, and end of life care. The way to look at these things is not in a vacuum. All of us may have our own opinions about right and wrong, but the field of medical ethics is actually one that has a body of research and accepted practice. It certainly is something we deal with frequently in the PICU. It may sound esoteric, but generally it isn’t. Even so, it can be complicated. But complicated or not, it’s also something all of us should know a little about. This is because, in fact, many of us will encounter these issues quite suddenly and unexpectedly with our loved ones, or even ourselves. It is good to be prepared and knowledgeable. The cartoon above suggests it’s all about the law and medical tradition. Really, it’s more complicated than that — and more interesting.
So what are the accepted principles of medical ethics? There are four main principles, which on the surface are quite simple. They are these:
1. Beneficence (or, only do good things)
2. Nonmaleficence (or, don’t do bad things)
3. Autonomy (or, the patient decides important things)
4. Justice (or, be fair to everyone)
Beneficence
The first of these principles, beneficence, is the straightforward imperative that whatever we do should, before all else, benefit the patient. At first glance this seems an obvious statement. Why would we do anything that does not help the patient? In reality, we in the PICU, for example, are frequently tempted to do (or asked to do by families or other physicians) things that are of marginal or even no benefit to the patient. Common examples include a treatment or a test we think is unlikely to help, but just might. Should we do it just because somebody wants it?
Nonmaleficence
There is a long tradition in medicine, one encapsulated in the Latin phrase primum non nocere (“first do no harm”), which admonishes physicians to avoid harming our patients. This is the principle of nonmaleficence. Again, this seems obvious. Why would we do anything to harm our patients? But let’s consider the example of tests or treatments we consider long shots — those which probably won’t help, but possibly could. It is one thing when someone asks us to mix an innocuous herbal remedy into a child’s feeding formula. It is quite another when we’re considering giving a child with advanced cancer a highly toxic drug that may or may not treat the cancer, but will certainly cause the child pain and suffering. Should we do it?
Autonomy
Our daily discussions in the PICU about the proper action to take, and particularly about who should decide, often lead us directly to the third key principle of medical ethics, which is autonomy. Autonomy means physicians should respect a patient’s wishes regarding what medical care he or she wants to receive. Years ago patients tended to believe, along with their physicians, that the doctor always knew best. The world has changed since that time, and today patients and their families have become much more involved in decisions regarding their care. This is a good thing. Recent legal decisions have emphasized the principle that patients who are fully competent mentally may choose to ignore medical advice and do (or not do) to their own bodies as they wish.
The issue of autonomy becomes much more complicated for children, or in the situation of an adult who is not able to decide things for himself. Who decides what to do? In the PICU, the principle of autonomy generally applies to the wishes of the family for their child. But what if they want something the doctors believe is wrong or dangerous? What if the family cannot decide what they want for their child? Finally, what if the child does not want what his or her parents want — at what age and to what extent should we honor the child’s wishes? (I’ve written about that issue here.) As you can see, the simple issue of autonomy is often not simple at all.
Justice
The fourth key principle of medical ethics, justice, stands somewhat apart from the other three. Justice means physicians are obligated to treat every patient the same, irrespective of age, race, sex, personality, income, or insurance status.
You can see how these ethical principles, at first glance so seemingly straightforward, can weave themselves together into a tangled knot of conflicting opinions and desires. The devil is often in the details. For example, as a practical matter, we often encounter a sort of tug-of-war between the ethical principles of beneficence and nonmaleficence — the imperative to do only helpful things and not do unhelpful ones. This is because everything we do carries some risk. We have different ways of describing the interaction between them, but we often speak of the “risk benefit ratio.” Simply put: Is the expected or potential benefit to the child worth the risk the contemplated test, treatment, or procedure will carry?
The difficult situations, of course, are those painted in shades of grey, and this includes a good number of them. In spite of that, thinking about how these four principles relate to each other is an excellent way of framing your thought process.
If you are interested in medical ethics, there are many good sites where you can read more. Here is a good site from the University of Washington, here is a link to the President’s Council on Bioethics (which discusses many specific issues), and here is an excellent blog specifically about the issues of end of life care maintained by Thaddeus Pope, a law professor who is expert in the legal ramifications. If you want a really detailed discussion, an excellent standard book is Principles of Biomedical Ethics, by Beauchamp and Childress.
(Guest Post: What follows is a fascinating and enlightening essay and book review by Maggie Mahar, who blogs on healthcare policy issues at her excellent blog Healthbeat, posted here with her permission.)
Miriam Zoll’s Cracked Open: Liberty, Fertility and the Pursuit of High Tech Babies is in part a moving memoir, in part a troubling expose of yet another unregulated corner of our healthcare system. In this case it is an industry that offers women everything from in-vitro fertilization (IVF) to another women’s eggs-for-sale.
Zoll titles her first chapter “One Egg, Please and Make it Easy.” If only it were that simple. She begins by acknowledging how naïve she was:
“I am an official member of the Late Boomer Generation. We grew up . . . . in the 1970s and ‘80s, watching with wide eyes while millions of American women—some with children and some not—infiltrated formerly closed-to-females professions like medicine, law, and politics. This exodus from the kitchen into the boardroom created a thrilling, radical shift in home and office politics, in the economy, and in relations between the sexes. ‘Shoot for the stars,’ some of the more thoughtful women advised us, ‘but don’t forget about the kids.’”
Zoll herself became one of the trailblazers. She is the founding co-producer of the original “Take Our Daughters to Work” Day, and on the board of “Our Bodies Ourselves.” In 2005, she became a Research Fellow at MIT’s Center for International Studies. There, her widely –published research addressed gender inequity and poverty in HIV/AIDS-affected households in sub-Saharan Africa.
At 35, Zoll married. At 40 she reports, she looked in the mirror, and decided: “It’s time to have a baby.” Finally, she felt confident that she would be a good mother. It didn’t occur to her that she might have trouble conceiving.
“We are the generation that . . . came of age at a time of burgeoning reproductive technologies,” she explains. “We grew up with dazzling front-page stories heralding the marvels of test-tube babies, frozen sperm, surrogates and egg donors; stories that helped paint the illusion that we could forget about our biological clocks and have a happy family life after—not necessarily before or during—the workplace promotions.”
Zoll goes on to chronicle her own long trek through our multi-billion-dollar fertility industry. At the beginning, she and he husband were as innocent as most couples who believe what the media had told them: “Science and technology have finally outsmarted Mother Nature. Just because you’re over 40, this does not mean that you can’t conceive.”
That final line is absolutely true. Each year in-vitro fertilization and other forms of Assisted Reproductive Technology (ART) produce miracles. The extraordinary joy that parents who thought that they could never have a child feel when holding their baby should never be discounted. When the right patient receives the right therapy at the right time, these technologies can heal broken hearts.
ART is still a medical experiment. Or, as Zoll puts it: “ART is a crap shoot.” In many cases, physicians don’t know why some couples succeed and others do not. No one keeps tabs on who wins and who loses. We have a National Joint Replacement Registry, a database of information that surgeons can consult as they learn why certain procedures work for certain patients while others go awry. But there is no official registry for in vitro fertilization—despite the fact it is an infant science shot through with uncertainties.
As Minnesota law professor Michele Goodwin and Judy Norsigian, Executive Director of Our Bodies Ourselves, warn in the Foreword to Cracked Open: “While the ‘better’ fertility centers now claim live birth rates of 50 percent or more, the national average remains at about one-third. It is easy to misinterpret pregnancy rates—which are high but often end in miscarriage—as live birth rates, which are much lower in comparison.”
Here are the facts: The most recent data from the CDC reveal IVF failure rates as high as 68 to 78% in women ages 35 to 40, and 88 to 95% among women 40-44. Meanwhile the “baby business” is a for-profit business. The industry’s mission statement is also a marketing statement: “It just takes one good egg.” Little wonder that so many would-be parents are seduced. They want to believe that their doctor is a fairy-godfather/mother who has just one desire: to make sure that they become parents.
“As a business, what makes the fertility industry unique is the combination of supply-side virtuousness and demand-side desperation,” writes Michael Cook, editor of Mercatornet. “The doctors and scientists who run the clinics can do no wrong. The women who want the babies will pay them whatever they charge.” But fertility clinics are run by human beings. Some are more truthful than others. Zoll describes her first visit to one.
“Michael and I were nervous and excited. The clinic literature cited studies claiming that well over two-thirds of all couples seeking treatment for fertility-related problems become parents. It didn’t occur to us then to ask if this statistic meant that two-thirds of parents birthed their own babies or a donor egg or embryo baby, or if they became parents through adoption or surrogacy. We were as green as could be about what to expect and what to ask, and we were eager to hear how the doctors thought they might help us.”
“That first day, my husband and I met with two health care professionals, one who examined my female interior and another who walked us through the ins and outs of the medical aspects of fertility treatments. A marble egg sat on a little pedestal on both staff members’ desks, and at one point during our meetings they each held it between their thumb and index fingers. . . .They smiled and said, verbatim: ‘Like we say here at the clinic, it only takes one good egg to make a baby.’ It was obviously the clinic’s mission statement.”
“I immediately thought that, if all we had to do was find one good egg, we were certainly the right candidates for the job. How hard could that be, really? . . . . I was in great mental and physical health. I exercised and practiced yoga regularly. I ate well. What more could a doctor ask from a patient? Little did I know that the process of finding one good egg would be a bit like panning for gold in a mine that had already been stripped of much of its bullion.”
A few weeks later, Zoll and her husband met with a veteran physician she would dub the “Silver Fox.” After reading the couple’s medical records, he looked Zoll straight in the eye: “‘The first thing I want to say is that you’re old.’”
“I winced as his words cut through me like a razor-sharp sword,” she remembers, “and then within a split second I found myself in a serious state of denial, fighting back the urge to tell him that he was the one with the white hair, not me. He was the old geezer in the room, not me. No sir, not me. All my life I had to convince people that I wasn’t as young as I appeared. I knew I was teetering on the brink of officially entering middle age, but I didn’t think I was there—yet. ‘Women your age have a harder time conceiving, especially if they have endometriosis, like you,’ he continued. ‘You should have come to see me when you were thirty.’ This veteran fertility specialist was horribly blunt. But he was right.”
Endometriosis is an often painful disorder involving tissue that normally lines the uterus growing outside the uterus. While it can be treated, endometriosis can lower a woman’s chances of conceiving. The first doctor should have told her this. This doesn’t mean that a woman diagnosed with endometriosis shouldn’t try ART. That is a personal decision. But a woman needs to know the truth about her chances so that she can make an informed choice.
When Zoll saw the Silver Fox, she harbored high hopes. “I was confident that, since my mother had birthed me later in life, I would have no trouble doing the same thing. During that first meeting with the Silver Fox, I proudly told him that my mother had been thirty-nine years old when I was born. ‘Just because your mother did it doesn’t mean you will too,’ he replied. ‘Do you think there’s a gene for birthing in middle age that your mother passed onto you?'”
“In response to that question, I distinctly remember that I blinked three times,” she writes. “Um, yes, think me an idiot, but actually I did believe that since mom had done it I could do it. Why would I think otherwise? For decades, the Sunday New York Times and People magazine had reported that it was possible to birth a baby later in life, and American pop culture is loaded with messages telling women that they can become pregnant when they are older. In the movie Parenthood, Mary Steenburgen and Dianne Wiest both play the role of older women who have no trouble birthing babies, and in Father of the Bride, a middle-aged Diane Keaton delivers a baby on the same day her 21-year-old daughter does. . . .Year after year, the headlines and cultural messages screamed out: ‘Relax and sit back. You’ve got science on your side.”
“But now this doctor was telling me that I might not have science on my side, after all. He was telling me that I had deluded myself with misinformation and false hopes about my own biology—and, according to global research, I am not alone . . . . In a survey of undergraduates in the United States conducted in 2012, two-thirds of women and 81 percent of men believed that female fertility did not markedly decline until after the age of 40. One-third of women and nearly half of men believed this marked decline occurred after the age of 44—an age at which IVF is least effective. A full 64 percent of men and 53 percent of women surveyed overestimated the chances of couples conceiving a child following only one IVF treatment. The study concluded: “The discrepancy between participant’s perceived knowledge and what is known regarding the science of reproduction is alarming and could lead to involuntary childlessness.”
Ultimately, Zoll would meet a doctor who advised: “In a situation like yours, where your hormones are not stimulating the kind of egg production needed for pregnancy, we like to recommend that couples think about egg donation or adoption.” This was honest advice.
Reluctantly, Zoll explored the idea of finding a donor: “I first entertained the possibility of working with a donor egg agency after the second IVF cycle failed. The very idea of Michael’s sperm fertilizing a stranger’s eggs and then having those embryos inserted into my uterus made me wince. But, given what the doctors had told us about the quality of my eggs early on, I wanted to be open to the idea of a donor—just in case. While some of the literature said there was great success with older women using younger women’s eggs, other data suggested just the opposite. Once again, it was a crapshoot: you either win or you lose, but the big question was, do you want to play the game?”
Zoll confides that “The first donor egg website I happened to stumble upon was a California agency where the majority of potential donors looked like contestants for the Miss California pageant. They were all slender, blonde, and buxom and their price tags were high, ranging from $8,000 to $10,000. Why did they call them donors, I wondered? I spent only five minutes on the site before I hastily clicked off.”
I felt like an eggless sociopath for even considering asking one of these young women to risk her health so that I might purchase her eggs.
“The vast majority of donors on this site and elsewhere in the United Staes were in their twenties. How and why do they decide to sell their eggs to someone like me? How do the donor agencies and these young women determine that their eggs are worth $8,000 while someone else’s eggs are worth only $5,000? Were blonde, blue-eyed donors always more expensive than brown-eyed, overweight donors? . . . . We were told on more than one occasion that it is not unheard of for infertile Ivy League alums to post a classified ad in campus publications offering up to $100,000 for an egg donor with high SAT scores, 36-24-36 body measurements, and a penchant for Mozart.”
Capitalism sets a price for eggs, depending upon a woman’s bloodline.
“One thing this boom in fertility medicine has done is to help us apply an economic value to women’s reproductive labor,” Zoll writes. “This may or may not be a good thing, depending on how you look at it. In today’s U.S. marketplace, a woman’s egg is valued at anywhere between $5,000 to $100,000 or more, depending on her bloodline. On average, though, let’s say an egg is worth between $5,000 and $10,000. Some people think it is immoral to put a price tag on genetic material and women’s reproductive hardware and capabilities. But, considering that the global fertility industry generates billions of dollars a year, why not calculate women’s economic contributions, too?”
Zoll makes a reasonable point. Pharmaceutical companies are paid a fortune for fertility drugs. Why shouldn’t the women who donate their eggs cash in too? Like Zoll, I, personally, am appalled by the idea of commerce that traffic in womens’ eggs. But men regularly sell their sperm. Shouldn’t women be able peddle their eggs? Here’s the difference: when men donate sperm they take no risk. By contrast harvesting eggs from a woman’s body is an invasive procedure and can affect her health. The drugs the donor must take are potent. Particularly when researchers are paying for the eggs, poor women may be exploited.
After Miriam’s second IVF cycle failed, she and Michael bravely advanced to a third. And finally, she became pregnant. Then the silver fox gave her the news: “The heartbeat is weak. . . You’ll miscarry within a week, most likely.’’ He told her this as he was leaving the office.
Inconsolable, Miriam and Michael embarked on a fourth IVF cycle, using “new super-drugs.” This time, they chose a young fertility doctor who leveled with them, explaining that “a female baby is born with millions of egg follicles that dwindle to about 400,000 by the time she reaches puberty.” But by the time she is 40, “’what remains are the eggs that were never very healthy in the first place. ‘The strong ones leave the roost early,’ he explained. “The robust eggs want to move out. They want to meet the sperm. The weaker ones stay behind.” Nevertheless, Zoll writes, “he was unable to resist the temptation of his clinic’s mantra.” And so he continued: ” Of course, that’s not to say that you don’t have some good eggs left.”
After 10 days of shots, vitamins and suppositories, Miriam went for her first ultrasound appointment. She remembers what the technicians said as she greased the probe and slid it into her vagina: “Well let’s see what’s happening in there.” The examination didn’t take long: “Okay, that’s it.”
“That was fast,” Zoll said as she stood up.
“There’s nothing there,” she said. “The doctor will call you.”
Finally, Zoll overcame her reservations and decided to look for an egg donor. She and Michael picked two. When doctors screened the first one, it turned out that she was infertile. That cost Miriam and Michael $4,000. Then the clinic explained that it couldn’t screen the second donor until it received another $4,000.
“But that’s ridiculous,” Zoll told the nurse. “The second donor just completed a cycle at a reputable hospital clinic that produced a pregnancy. Why can’t you use their tests?”
“Well, we have to run our own tests,” the nurse replied. Finally, she explained “you have to realize that we have to make money somehow. These tests can’t be free.”
Because Zoll put up a fight, the clinic eventually waived the fee. The donor was screened, and the doctor retrieved 12 eggs that were fertilized with Michael’s sperm.
Then they got the news that crushed them, once again. None of the 12 eggs fertilized.
Zoll recalls her conversation with the doctor: “’It’s really quite shocking to us,’ he said in that tone we had heard before. It was the tone that implied that the clinic was not responsible for the outcome, and I suppose that in many ways, they weren’t. Doctors could try to control nature, but they couldn’t manipulate it completely. Still, the clinic has approved the donor. Now, the doctor was saying ‘there is likely something wrong with the donor’s eggs. . . . . . I do hope you will try another donor cycle, but I don’t recommend that you use this woman again .. . Given the drugs she was taking, she should have produced many more eggs than she did.’”
“I didn’t say a word, I just sat there listening,” Zoll recalls. “Our donor had helped another couple become pregnant only a few months earlier. Maybe she should have taken more time off between cycles before working with us. Why hadn’t the doctors flagged the possibility that her reproductive system was oversaturated with drugs that were likely wreaking havoc on her ovaries?”
At this point Zoll realizes that “We had spent thousands of dollars on IVF and even more on the donor egg process, and through it all, no one was accountable for the outcomes. The clnics were not accountable. The pharmaceutical companies that made the drugs the donor and I ingested were not accountable. . . . . Thousands of dollars earlier this same doctor had told us that Donor #2 was a fine candidate . . . . Now. . . he was encouraging us to spend more money and select a different donor, perhaps a younger donor, or a donor with purple eyes and blue hair , who might give us a better yield. What kind of wishy-washy medicine was this?”
Still, Zoll admits: “We had willingly and under no duress paid ridiculous amounts of money for access to medical technologies that we were sure would work and did not. We paid for the chance to hope. We paid for the chance to try.
We were the only ones who are accountable.
Of course, Zoll is right. But still, the question of accountability haunts medicine. When a patient submits to medical treatment, there are no guarantees and no warrantees. If he is unhappy with the results of an operation, he cannot return it. If the patient dies, the surgeon and the hospital still must be paid. This is because most of medicine is still such an uncertain science, fraught with unknowns. If hospitals and physicians were paid only when they were successful many, if not most, would only take the easiest cases. But this is all the more reason why patients need to be fully informed about risks and the odds of success before they choose a course of treatment.
Instead, silence reinforces the fairy-tales
When treatments fail, Zoll writes, “most couples never want to talk about it. And who could blame them.”
There was a cultural taboo — reinforced by the clinics themselves, that we shouldn’t talk about our infertility or our miscarriages or the inability of science to solve our reproductive health challenges. It was that absence of truth-telling that made the success stories sensationalized in the media so dangerously misleading.
It is terribly important that couples tell the truth about their experiences. At the end of her book, Zoll explains: “By sharing my experience, I’m hoping that others will begin to speak out and share theirs, whether treatments were successful or not. For those still recovering, I invite you to cast off your silence and contribute to expanding an open and honest consumer-driven discussion about these life-altering technologies. Men and women contemplating fertility treatments need to hear your perspective . . . By sharing your experiences you can help create a more balanced perspective.”
Best of all, Zoll points readers to a place where “if you would like to share information about your experience, please visit the voluntary registry at Dartmouth-Hitchcock Medical Center.” (I am far from suprised that Dartmouth has taken on this task. It remains one of the most patient-centered institutions in the nation.)
How Does the Story End? A Postscript
I won’t disclose whether a child ever found Miriam and Michael. It is their story, and I don’t want to spoil the ending. Cracked Open is available in paperback and it’s an excellent read.
If you pick up the book, you will find out, among other things, how they met, and, perhaps most importantly, why they didn’t marry in their 20s.
Here, I would like to add a postscript.
Cracked Open is meant as a cautionary tale for women who may think that they should first become successful in their careers, then plan to have a child when they turn 40. Both media and market hype have convinced many that they can plan a pregnancy when they choose. The CDC’s numbers reveal that his just isn’t true.
I should add that the story of Michael and Miriam’s roller-coaster relationship when they were in their 20s convinces me that if they had married then, they would have divorced within a few years.
Miriam acknowledges that she wasn’t ready for marriage: “This kind of ‘push-me-pull-me’ love eventually ended our relationship and helped motivate me to begin therapy. Difficulties from childhood were now spilling over into my life. I needed to make sense of it all. This was an excellent reason to delay marriage and children. A great many twenty-somethings—women as well as men—are not ready for marriage and parenthood.”
When writing about Cracked Open, I worried that this tale could send a 33-year-old single woman (or her mother) into a panic –though I know this is not Zoll’s intention. Cracked Open is not urging women to let the “tick-tock” of their biological clocks rush them into marriage.
Delaying motherhood because you’re caught on a fast-track and just don’t know how to get off is one thing. Postponing children until you and the right person find each other at the right time is another.
Not everyone would agree with me. Zoll reports that “an article published a few years ago in the British Medical Journal, advised women to start having children before they turn 30: ‘Surveys of older mothers show that half say they delayed because they had not yet met a suitable partner. Maybe instead of waiting for Mr. Right they ought to wait for Mr. Good-Enough, if they want children.’ If Mr. Good-Enough means ‘he doesn’t earn as much as my sister’s husband– but we have such a good time together, and I know he’ll be a great father,’ that’s fine. But if it means that when you think about spending 30 or 40 years with him, you sigh . . . all I can say is “don’t do it.”
I have known so many women who found the right husband after 35. Out of nowhere, he appears. When that happens, it’s not a difficult decision. You recognize each other.
At that point, women have many options including in vitro fertilization, finding an egg donor, and adoption. Not long ago, a friend who met her husband in her late 30s told me: “When I turned 40, I realized I could take $20,000 and go to a fertility clinic. Or I could take the same $20,000, go to Russia and adopt a child.” She has never regretted her decision.
Those are not a woman’s only options. Some will decide that rather than struggling to become the perfect 40-something mother, they would prefer to become the perfect aunt. It’s a personal choice, not a medical decision.
(Thanks, Maggie — and thanks Ms. Zoll for writing this excellent and heartfelt book.)
This is an excerpt from my latest book. The particular chapter is about ear infections — what they are and what they would look like if you could see the microscopic action up close. Before you can understand an infected ear, though, you need to see what a normal one looks like. The idea in this passage is to describe what you would see if you were inside a combination tiny submarine and all-terrain vehicle and made a journey up the back of the nose, up the tube connecting the nose to the middle ear, and then into a normal middle ear.
_ _ _ _ _ _ _ _ _
Finally, you pop through a tight opening and find yourself in the middle ear. You land your craft on the floor of this air-filled cave to have a good look around. In its tiny way, it is a majestic sight. Your searchlight reveals high above you, like stone arches in the Utah desert, a series of three delicately interconnected bones. The bones span the open space from one side of the cavern to the other. One wall of the cavern is formed by the translucent, pearl gray eardrum. When you shine your light on it you can see right through it, revealing some clumps of earwax in your son’s ear canal beyond. You cringe a bit, wondering if you should have cleaned his ears out with a cotton swab. (The answer is no—never stick a swab deep into his ear canal. Gazing at the delicate structures around you, it is clear why: they are easily damaged.)
Shining your light back at the bony arches in the space above, you see the first of these bones presses up against the inner surface of his eardrum. The end of the third bone lies against the far wall on what looks like a tiny, oblong window. This structure has a matter-of-fact name: the oval window. There is another opening nearby, called the round window, because that is what it resembles. Both windows are covered by a thin membrane. Behind the windows lies the inner ear, but you cannot see it because it is recessed into the wall. The middle bone, directly above you, connects the other two bones with each other, linking eardrum to oval window.
What you are looking at is the astonishing mechanism by which sound waves in the air are transformed into a sound we can hear inside our brains. It works like this: When sound waves strike the eardrum, it vibrates. The vibrations cause the connected series of three bones to wiggle, passing the vibrations down the chain to the delicate membrane covering of the oval window. As this membrane vibrates, it causes the fluid within the inner ear to move. Sticking out into this liquid are the so-called hair cells, which get their name because they do look hairy; from the inner ear surface a matrix of delicate hairs sticks out into the liquid. When the liquid moves, the tiny hairs move back and forth. The hair cells connect directly to nerves that run into the brain, which finally translates these minute twitches and wiggles into what we perceive as sound. The little round window is necessary because, without its complementary movement in and out, the vibrations from the third bone pushing on the oval window would be unable to move the fluid in the inner ear. You cannot compress a liquid inside a rigid container—in this case, the rigid container is the skull bone encasing the inner ear.
The sensitivity of this chain of bones, membranes, and tiny hairs is another amazing aspect of hearing. It allows us to localize, quite precisely, from which direction a particular sound is coming. Our brains do this by comparing the intensity of the sound between our two ears: we can turn our head until the sounds are equal on both sides in order to locate the direction of a sound. This explains those instances when we find it difficult to localize a sound—in a cave, for example. Any situation in which sound waves are reflected off surrounding walls or structures can make them strike our eardrums in confusing patterns. We can twist our heads around to try and find the source, but if it the sound waves come from several directions our brains will remain confused.
Hearing is indeed a fantastic mechanism. As your searchlights illuminate the overarching mini-cathedral of the middle ear, your son hears something, and you see the system function in all its glory—eardrum vibrating, connecting bones quivering, and the oval and round windows shimmering as they move. Inside the windows, you glimpse the hair cells waving. Suitably awed by the grandeur of what you have seen, you exit his middle ear and nose the same way you came in.
This is another post about how non-physicians can understand how physicians use evidence. As I noted before, medical evidence has a hierarchy of reliability. The least reliable of these is expert opinion. This seems counter-intuitive: why is expert opinion the worst sort of evidence? Should not the experts know what they are talking about? In general, of course, experts do know what they are talking about — that is what makes them experts. But a closer examination of the matter shows why this kind of evidence is the weakest and most subjective; after all, it is one person’s opinion (or sometimes a committee of persons’ opinions), and opinions can be incorrect.
We need to look closely at just why a particular individual is considered an expert, and by whom. Credentials are important: where did the person obtain her training, where does she work now, and what is her standing among her peers? These seem obvious questions to ask, but these days an astonishing number of people with dubious or no credentials can write a book, put up a website, or start a blog, and, if they are persuasive marketers, can convince others they are experts. Fortunately for parents, the same wide-open quality of the internet allows one to search the background, credentials, and accomplishments of any putative expert. Wise parents will do this as a matter of course before deciding whether to take the expert’s advice on any important matter about their child’s health.
Experts who advise you to do one thing or another with your child typically base their advice to you on their own interpretation of the available medical research. They have the knowledge and training to understand the often esoteric medical literature. In addition, most experts themselves do research in the relevant field. Those are important and useful things. However, there are still good reasons why we should regard such opinions as the worst kind of data — better than nothing, but sometimes only barely so.
For one thing, the reason an expert holds a particular opinion may be because she was taught that way by her teachers, who may have, in turn, been taught the same thing by their teachers. Medicine is practical and empirical enough that such received, traditional opinions will not be tossed out unless they are consistently wrong. It is also true we physicians venerate our medical forebears to the extent that misguided opinions can occasionally persist long after they should have been discarded. So sometimes the answer to why doctors do something a particular way is that we have always done it that way.
Experts also form their opinions based upon what they have seen in the past. If their experience is long, often they have seen quite a few instances of whatever is under discussion, and that experience should count for something. On the other hand, memory is a tricky thing; sometimes we recall things in ways that can ultimately prove misleading. For example, the more striking and dramatic things tend to stay in our minds better than the more mundane things, and medical experts are not immune to this phenomenon. For example, I know that I remember unusual manifestations of certain cases for decades, and this inevitably colors how I approach the next child with that particular problem. Even though I know the case was unusual, I naturally think of its circumstances whenever I care for another child with whatever the disorder was. This is an example of what we call recall bias.
There are other kinds of bias that may affect the judgment of medical experts, and some of them are not innocent things like tricks of memory. Medical experts are no different from other kinds of experts, such as foreign policy pundits or stock market analysts, in that we, too, may have agendas that are not obvious to parents listening to our advice. Any controversial subject will lead to partisanship, and medical debates are no different. Parents considering the advice of medical experts should be alert to what a particular expert’s agenda might be. This is not necessarily a sinister thing; I think the great majority of experts advocating one position or another do so because they truly believe it is the correct one. But it is still a real thing.
Sometimes, however, medical experts may have agendas that are not so innocent. For example, there have been recent examples of experts touting one treatment over another when they have an undisclosed interest in the outcome. The conflict of interest could be intellectual, such as past friendships or associations with researchers of a particular treatment, or they could be crassly commercial. The ethical boundaries are, in theory, quite sharp, but there have been well-known examples of medical experts recommending a particular treatment when they have a financial conflict of interest regarding the outcome.
The best experts, of course, are the ones who tell you the basis of their opinions. They do not just pontificate about what is best for your child — they tell you how their reading of the best evidence led them to their informed opinion. They interpret for you the meaning of the scientific evidence. On the whole, most medical experts will do this for parents. Even so, it is a good thing for parents not to take whatever the experts say entirely on faith; it is better to have some grasp of how medical evidence is collected and analyzed. And besides, even experts can be wrong.
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