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Do We Really Need CT Scans? (If You Thought That Question Was A Settled Question, Please Keep Reading.)

Posted Feb 21 2010 12:00am




Did you know that CT scans, commonly called “CAT scans,” are a bad idea? Actually, only about half of them are bad--although, of course, we don’t know which half. But whichever half it is, CT scans are a bad idea: “a technology that just doesn’t compute.” So asserts writer Thomas Goetz, the executive editor of Wired magazine, in an article for TheBigMoney.com. If it seems strange that a Wired guy would be dumping on technology, well, keep reading. As we shall see, a paradox of Bay Area politics--Wired is based in San Francisco--is that folks out there take it as a given that technology is good for just about everything, except healthcare. On healthcare, folks living by Golden Gate seem to prefer holistic and empowering approaches, including, strangely enough, support for Obamacare-type rationing.

Evidently searching for a clever hook for an article, author Goetz called his piece, “I Wanna CT Scan Your Hand: How the Beatles created our soaring health care costs.” Actually, the Beatles had noting to do with it; Goetz is teasing his readers because computed tomography, or CT, was invented in 1967 by a British engineer who happened to work at the Beatles’ then-record label. If all that seems a bit of a stretch, then welcome to the world of opportunistic book promotion. Goetz has a new book to promote, from which the CT article is an excerpt.

Goetz freely concedes, “CT technology has been a boon to medicine, aiding in the diagnosis of everything from broken bones to kidney disease to cancer.” Yet, he continues:

CT scans have also been a major factor in the explosion of health care costs in the United States. These days, these very expensive machines—along with their high-resolution brethren, MRIs [magnetic resonance imaging]and PET [positron emission tomography] scans—are sometimes used indiscriminately, often in an effort to generate a diagnosis rather than confirm one.

Note the planted assumption here: “explosion of health care costs”--which is another way of saying that “health care, consuming one-sixth of our economy, costs too much, and we all know that the cost of health is a more urgent problem than the lack of health.” One response to that planted assumption, of course, is that healthcare accounts for one-sixth of our wealth, and that both our wealth and our health are improved by the best possible diagnostic tools--tools for diagnosing “everything from broken bones to kidney disease to cancer.” But Goetz is on a different track:

Despite their high resolution, CT scans are still blunt instruments. They can actually introduce too much information into a situation. A high-resolution image of the inside of the body reveals so much that everything begins to look like an anomaly or a potential problem. As Shannon Brownlee wrote in her 2007 book Overtreated, “for every scan that helps a physician come to the right decision, another scan may cloud the picture, sending the doctor down the wrong path.” Which is exactly why, however useful they are in specific cases to ascertain specific diagnoses, they are particularly unsuited to being used as a screening tool—in other words, deployed broadly among asymptomatic pool of people. Which, unfortunately, is what many people are saying CT scans should be used for.

So there we have it: Goetz, citing Shannon Brownlee’s hugely influential book, Overtreated: Why Too Much Medicine Is Making Us Sicker and Poorer, says that we are overusing CT scans and we should use them less. And so, Goetz concludes:

The fact is that, like a lot of medical technology, a CT scan can do a lot of good in particular circumstances. But too often, the enthusiasm for CT scans outstrips its utility. And the result is a technology that just doesn’t compute.


It’s legitimate, to be sure, to argue over every aspect of medical science, based on new concerns and new information. But we might wonder what we should have done in other situations when we faced a 50 percent failure rate. At one time or another, half of all candlestick telephones, or vacuum-tube radios, or biplanes, were failing. In each case, the answer was to learn from mistakes, commit to the best practices, and push on through to the solution.

Indeed, it’s a strange kind of retro-thinking that leads one to say, “We have confronted a problem, and the answer is to turn backward.” That’s the same “limits to growth” thinking that we saw in the 70s, which, in turn, gave us the Jimmy Carter presidency, emphasizing rationing and “malaise.” And we can see the same thread of scarcity-think running through the Hillarycare healthcare plan of the early 90s, and the Obamacare plan of the last year or so. In each instance, the elite refrain has been, “We have too much, we use too much, it’s bad for us, and so we, the powerful, say, ‘Let’s cut back--and if you, the American people, don’t agree, we’ll try to force it on you!’” But of course, the elites don’t have that much power, at least not when they are pushing deeply unpopular programs. And so, in 1980, 1994, and 2010, the “limits to growth” agenda was defeated at the ballot box.

OK, that’s the politics of scarcity. As labor leader Samuel Gompers declared, the American people want “more,” not less.


But what about the substance of Goetz’s argument? He writes, for example:

Most technologies get cheaper as they get more popular. DVD players, digital cameras, flat-screen televisions, and pretty much every other technology you can think of has observed this pattern. But that’s not at all what’s happened with CT scans.

The resolution of a CT scan is measured in slices. Each rotation of the X-ray unit around an object generates a certain number of cross-sectional images; those cross-sections are called slices. The more slices per rotation, the higher the resolution of the image, just like a higher-resolution digital camera produces a sharper image. Since the 1990s, CT scans have leapt from four to eight to 16 to 32 to 64 slices, with a dramatic improvement in the quality of the machines. Yet the price of CT scanners has stayed consistently and breathtakingly high. From 1974 to 2004, the list price of a CT scanner increased from $385,000 to $2.2 million, a nearly sixfold increase (with inflation accounting for only about $1 million of that increase). Sure, that $2.2 million buys a better machine than $385,000 did 30 years ago. But the price arrow points in the opposite direction from that seen with other technologies, where the economics of scale and Moore’s law have consistently driven costs down, even as quality goes up.

Now we might begin by noting that in real terms, using Goetz’s figures, the price of a CT scanner rose about 55 percent in 30 years, from an inflation-adjusted $1.4 million to $2.2 million. That’s a big increase, but, as Goetz notes, the number of X-ray “slices” a machine can perform has risen from four to 64. That’s a 16-fold increase, or 1600 percent. Which is to say, the increase in the quality of CT machines has risen almost 30 times faster than the increase in the cost. If that’s not a Moore’s Law-level increase, it’s pretty close.

But Goetz prefers to label the evolution of CT scanners as an example of “market failure,” which is not surprising, he says, because “the health care industry is beset by market failure.” One putative failure is the just-cited price of the machines; another is personnel costs. He notes, for example, that diagnostic radiologists earn a median income of $361,000 a year. Is that really an outrageous amount for someone who learned and trained for a decade, and who is charged with diagnosing “everything from broken bones to kidney disease to cancer”?

But of course, if we really wanted to see the price of CT technology fall, we would use more of it--much more.

That’s the key point: more, not less. Going back to the beginning of the industrial revolution, more is the driver. As Goetz says, the price of electronic goods has fallen steadily--but only as the quantity of those goods has expanded dramatically. That is, 25 years ago, only a handful of people had portable phones--defined as bricklike things that worked only when they were in a good mood. But now, almost five billion people around the world have cell phone subscriptions. Yet as the quantity increased by an astronomical amount, the quality increased as well. The humblest cell phone made today is a better and more reliable instrument than the best cell phone of even a decade ago.

Thus the paradox of a certain strand of thinking: Technology is a good thing, and more technology is better--but not for healthcare. For scarcity-thinkers, healthcare as a separate category, separate from everything else, where “less is more.” Indeed, a chapter in Brownlee’s book is entitled, “When Less Is More.”

Moreover, according to this techno-minimalist environment, there’s little room for the next breakthrough. And so, for example, what would these less-is-more types make of General Electric’s V-Scan, a portable ultrasound imaging tool? The V-Scan, which GE happily compares to the “tricorder” in the old “Star Trek” TV series, is potentially the beginning of something bigger than CT Scans, offering the prospect of constant, non-invasive health monitoring. And if the cell phone precedent is any guide, the V-Scan-like portable medical device technology will get better as it gets cheaper and more abundant. We must hope that America can keep its edge in such healthcare innovation, that such design and manufacture isn’t chased overseas by misguided policies aimed at “saving money,” or, as they say in Washington DC, “bending the curve.”

So let’s hear it for the CT scan, and all its spinoffs. Someday, if the price is allowed to fall, thanks to the engine of mass production, we will all have some sort of medical imaging/diagnosing device, just as we all have TV sets or microwave ovens. And thus we will be healthier. And if we remember to make them in the US, we will be richer, too, as we export those machines all over the world.

PS: For a better look at the value of CT scans, and subsequent life-saving innovations, we might look to this essay in Parade magazine, from a great doctor, NIH director Francis Collins.
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