(This article was originally published at Statistical Modeling, Causal Inference, and Social Science, and syndicated at StatsBlogs.)
Atul Gawande (the thinking man’s Malcolm Gladwell) asks:
Why do some innovations spread so swiftly and others so slowly? Consider the very different trajectories of surgical anesthesia and antiseptics, both of which were discovered in the nineteenth century. The first public demonstration of anesthesia was in 1846. The Boston surgeon Henry Jacob Bigelow was approached by a local dentist named William Morton, who insisted that he had found a gas that could render patients insensible to the pain of surgery. That was a dramatic claim. In those days, even a minor tooth extraction was excruciating. Without effective pain control, surgeons learned to work with slashing speed. Attendants pinned patients down as they screamed and thrashed, until they fainted from the agony. Nothing ever tried had made much difference. Nonetheless, Bigelow agreed to let Morton demonstrate his claim.
On October 16, 1846, at Massachusetts General Hospital, Morton administered his gas through an inhaler in the mouth of a young man undergoing the excision of a tumor in his jaw. The patient only muttered to himself in a semi-conscious state during the procedure. The following day, the gas left a woman, undergoing surgery to cut a large tumor from her upper arm, completely silent and motionless. When she woke, she said she had experienced nothing at all.
Four weeks later, on November 18th, Bigelow published his report on the discovery of “insensibility produced by inhalation” in the Boston Medical and Surgical Journal. . . . The idea spread like a contagion, travelling through letters, meetings, and periodicals. By mid-December, surgeons were administering ether to patients in Paris and London. By February, anesthesia had been used in almost all the capitals of Europe, and by June in most regions of the world.
That was the happy story of the rapid acceptance of an innovation. Next comes the frustrating story:
Sepsis—infection—was the other great scourge of surgery. It was the single biggest killer of surgical patients . . . In the eighteen-sixties, the Edinburgh surgeon Joseph Lister read a paper by Louis Pasteur laying out his evidence that spoiling and fermentation were the consequence of microorganisms. Lister became convinced that the same process accounted for wound sepsis. . . . During the next few years, he perfected ways to use carbolic acid for cleansing hands and wounds and destroying any germs that might enter the operating field. The result was strikingly lower rates of sepsis and death. You would have thought that, when he published his observations in a groundbreaking series of reports in The Lancet, in 1867, his antiseptic method would have spread as rapidly as anesthesia.
Far from it. . . . It was a generation before Lister’s recommendations became routine and the next steps were taken toward the modern standard of asepsis—that is, entirely excluding germs from the surgical field, using heat-sterilized instruments and surgical teams clad in sterile gowns and gloves.
Pretty annoying, huh? Gawande asks why, and shoots down a couple of natural explanations:
Did the spread of anesthesia and antisepsis differ for economic reasons? Actually, the incentives for both ran in the right direction. If painless surgery attracted paying patients, so would a noticeably lower death rate. Besides, live patients were more likely to make good on their surgery bill. . . .
Maybe ideas that violate prior beliefs are harder to embrace. To nineteenth-century surgeons, germ theory seemed as illogical as, say, Darwin’s theory that human beings evolved from primates. Then again, so did the idea that you could inhale a gas and enter a pain-free state of suspended animation. . . .
The technical complexity might have been part of the difficulty. Giving Lister’s methods “a try” required painstaking attention to detail. . . . But anesthesia was no easier. Obtaining ether and constructing the inhaler could be difficult. You had to make sure that the device delivered an adequate dosage, and the mechanism required constant tinkering. Yet most surgeons stuck with it . . .
And then he gives his theory:
So what were the key differences? First, one combatted a visible and immediate problem (pain); the other combatted an invisible problem (germs) whose effects wouldn’t be manifest until well after the operation. Second, although both made life better for patients, only one made life better for doctors. Anesthesia changed surgery from a brutal, time-pressured assault on a shrieking patient to a quiet, considered procedure. Listerism, by contrast, required the operator to work in a shower of carbolic acid. Even low dilutions burned the surgeons’ hands. You can imagine why Lister’s crusade might have been a tough sell.
This has been the pattern of many important but stalled ideas. They attack problems that are big but, to most people, invisible; and making them work can be tedious, if not outright painful. . . .
Roaches
The above all makes sense, but I think there’s something else going on, something I find difficult to formulate but I think is real.
The example I have in mind is roach extermination. When I worked with Ginger Chew and her colleagues in the school of public health at Columbia several years ago, I learned that the way to get rid of roaches in your apartment is to clean up your apartment, throw away all the open food, put boric acid in the cracks in your floor and walls, and seal up the cracks. It’s not easy but it does the job. But that’s not what they do in the Columbia-owned-and-operated building where I live. What they do is, every month they put a signup sheet up by the elevator and then an exterminator comes into the building and bombs the apartments of everyone on the list. The same people sign up every month, of course. Instead of thinking, “Hey, bombing doesn’t work,” they seem to think that it’s something they need to do monthly. Good business for the exterminators but not so effective at getting rid of roaches.
So why do they do it that way? One thing I’m definitely not going to do is talk with my neighbors and suggest they try a different approach. My impression is that people get very defensive about things like this. Also, I’m no roach expert; really I’d want to bring someone in from the school of public health to have this conversation.
Anyway, my impression is that people like any treatment that feels like “pushing a button” and they don’t like anything that feels like work. And if you tell people that pushing the button doesn’t really work, they get all bristly on you. Even though, in this case I think the effective treatment is ultimately less work than the bomb. Unfortunately, Columbia has it set up so they bomb for free, but they don’t provide a free cleanup and sealing service.
P-values
I feel like there’s something similar going on in scientific research, when statistically significant p-values are used to declare victory (for some recent examples, see here and here and here and here and here). I know that these methods have become popular—but, then again, my neighbors are getting their apartments bombed for roaches every month, they just keep on doing it. Pushing that button.
Please note: the previous paragraph is not an argument that there’s a big problem with p-values in scientific practice. Rather, conditional on you already agreeing with me that there’s a big problem with p-values in scientific practice, the previous paragraph is a speculation of one reason why this has happened.
P.S. Regarding the roach bombing, see this informative comment from Ryan Welch.
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