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By Michael White | October 24th 2008 10:32 AM | 11 comments | Print | E-mail | Track Comments
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About Michael White

Welcome to Adaptive Complexity, where I write about genomics, systems biology, evolution, and the connection between science and literature, government, and society.

I'm a biochemist


... Full Bio

Newt Gingrich, John Kerry, and someone named Billy Beane (I have no clue who he is) argue that medicine is not yet sufficiently data driven.:

In the past decade, baseball has experienced a data-driven information revolution. Numbers-crunchers now routinely use statistics to put better teams on the field for less money. Our overpriced, underperforming health care system needs a similar revolution...

Remarkably, a doctor today can get more data on the starting third baseman on his fantasy baseball team than on the effectiveness of life-and-death medical procedures. Studies have shown that most health care is not based on clinical studies of what works best and what does not — be it a test, treatment, drug or technology. Instead, most care is based on informed opinion, personal observation or tradition.

Very true. Their call for evidence-based, data-driven medicine should be heeded, but you should know that the medical community has been on this for years now. It doesn't mean that the problem is solved, but today's medical students are being intensively educated in evidence-based medicine, and at the leading academic medical centers this is the way medicine is frequently practiced. Today's medical students are told that being a good physician includes knowing how to find and evaluate data, including increasingly common large-scale data sets that have to be evaluated using statistical models.

The change in the medical community isn't going to happen overnight, but the educational element has been a major priority at medical schools for years now. The current generation of physicians coming out of medical schools will eventually make evidence-based medicine standard practice.

Yet there is a chance of going too far towards number-crunching. Some authors have suggested that a physician's judgment can largely be replaced by computer models, just as baseball talent scouts are put to shame by someone with piles of stats and a computer. In many fields, from finance to wine evaluation to baseball, going by the numbers looks like the "new way to be smart." But human biology is a lot messier than baseball, and accurate prediction involves more numbers than we currently have available. The error margins of models we could make today would be unacceptably high. Right now, the best solution is producing physicians who are comfortable with both data and professional judgment.

To their credit, Beane, Gingrich and Kerry emphasize this point:

Evidence-based health care would not strip doctors of their decision-making authority nor replace their expertise. Instead, data and evidence should complement a lifetime of experience, so that doctors can deliver the best quality care at the lowest possible cost.

It goes without saying that to practice evidence-based medicine, you need evidence. This evidence comes from three major efforts: basic research, to understand the biology behind disease; translational medicine, which converts basic research into clinical practice; and clinical research, an effort to continuously evaluate, over the long-term, every aspect of how we practice medicine.

In order to do this effectively, we really ought to reorganize how the National Institutes of Health funds research. Right now, the NIH is divided up into disease-based institutes, but so much of today's research cuts across many institute boundaries. The NIH should reorganize with a center focused on basic research, one focused on translational medicine, a drug trials institute, and one along the lines of that proposed by Beane, Gingrich and Kerry - an institute that sponsored both sponsors clinical research and makes available in one place best-practices guidelines for busy physicians.

The most important point is this: while we're all hoping that new science will find new disease cures, we can already make big improvements in our health care by making rational decisions grounded in knowledge that is already available.

Comments

Hank's picture
Newt Gingrich, John Kerry, and someone named Billy Beane (I have no clue who he is) argue that medicine is not yet sufficiently data driven.:


Beane is GM for the Oakland A's, who consistently put out a decent baseball team despite lacking the budgets of the Yankees or Dodgers. 

It's understandable not to know who he is.   They're an American League team and you're in the best NL city in the country. 

Anyway, big-market teams have it easy; they can make an educated guess about future performance based on past performance.   Beane went a different way, to try and figure out which players would have that success but who weren't found by scouts that often went just by physical skills.  There's a pretty good book about him - "Moneyball."  The numerics he used (he didn't invent them, he just made them popular) looked at the value of getting on base more than batting average or homers as the overall determining factor in team wins.   

And win they do.  They just can't win in the playoffs that way.

adaptivecomplexity's picture
I figured he was somebody important. It's interesting that Beane's methods are good for making a decent team, but not a playoff-winning team. I think modeling is great ( I would love to model celllular systems the way Beane models baseball), but maybe human judgment isn't as obsolete as it's been made out to be.

"Right now, the best solution is producing physicians who are comfortable with both data and professional judgment."

You cite Ayers disapprovingly, but he talks quite a bit about using both, comparing two models of integrating the two:

1) Use regressions and numerical techniques to get a prediction or suggested decision, then allow the physician to take that into account in her judgment
2) Use physicians' judgments as another class of data to feed into the formal model

The second approach generally outperforms the first, as doctor overconfidence and poor calibration means that most of the time when they override the model they make things worse.

"Right now, the NIH is divided up into disease-based institutes, but so much of today's research cuts across many institute boundaries. The NIH should reorganize"

That would seem to be best for advancing medicine and human health, but the disease-based organization stems in significant part from the fact that political mobilization for medical research is disease-driven. When someone has a relative die of cancer X, they try to support research into cancer X, rather than thinking the generalized, "my relative died of disease, I am going to encourage the development of better treatments for disease." So this could be politically difficult, and if successful it might weaken the strength of lobbying for more medical research spending.

adaptivecomplexity's picture
When someone has a relative die of cancer X, they try to support research into cancer X, rather than thinking the generalized, "my relative died of disease, I am going to encourage the development of better treatments for disease."

I see the point, but I would guess that most people who are proactive about promoting research on a particular disease contribute to organizations like Damon Runyon and other specialized private foundations. When it comes to lobbying Congress for money, I think that even a restructured NIH could still make a strong case by providing a breakdown of funding by disease - 'we're doing this for disease X, this much for disease Y', etc. If you make the info available to the public from an NIH website (say, a search page where people can search for research abstracts and funding amounts by disease), you make it clear that the NIH hasn't abandoned disease.

As far as Ayers goes, I find that he's too sanguine about leap in complexity you get when go from predicting loan repayment or wine quality to predicting clinical outcomes. Maybe I'm misreading Ayres, but the way the issue is framed in his book makes it sound like Ayres thinks physicians could soon become just like the wine supercruncher in the opening chapter - input numbers for a few variables, and out comes your answer with an appropriate confidence interval. It doesn't take much skill to be a wine expert or an internist that way.

If that were possible, it would be great. In reality, it's going to take just as much skill and training to make medical decisions with these models as it does to make medical decisions today (but the decisions will hopefully be better). That's what gets lost in Ayers' book.

adaptivecomplexity's picture
I'm still not clear about the point you're trying to make.

I'm arguing that the practice of medicine will not (at least in the near future) become like the fairly simple examples of wine prediction or baseball talent selection, where a physician's judgment is completely replaced by an algorithm. However, medicine does have to become more data-driven, meaning we need physicians who have both good judgment and the ability to use computational tools or checklists or whatever to help them make evidence-based decisions in complex situations. It's a more complex situation than the one I recall Ayers describing.

I agree that medicine will not be fully deskilled for quite a while (although it' is extremely important to remember that less knowledgeable nurses and nurse practitioners already do just as well or better at patient care for much of medicine, and could be used much more often if not for regulatory restrictions), but I think there are large areas where the doctor's judgment should be overridden by relatively simple algorithms (where those algorithms include provisions for how to account for disagreements from physicians, e.g. by dividing objections into categories).

"However, medicine does have to become more data-driven, meaning we need physicians who have both good judgment and the ability to use computational tools or checklists or whatever to help them make evidence-based decisions in complex situations."

The argument is that if you let physicians have the final say they systematically override the formal models too often, and that the harm to patients from this outweighs the rare cases where the physician is right, so you need to constrain physician judgment with firm rules. This is an old result for medical expert systems: even if a doctor knows that in 90+% of cases of physician-expert system disagreement the computer is right, he or she will still consistently claim that in THIS case human judgment wins. This phenomenon means that adding a human veto often has a negative effect on decision quality.

adaptivecomplexity's picture
OK, thanks for the clarification, I see what you're saying now.

This is an old result for medical expert systems: even if a doctor knows that in 90+% of cases of physician-expert system disagreement the computer is right, he or she will still consistently claim that in THIS case human judgment wins. This phenomenon means that adding a human veto often has a negative effect on decision quality.

Call me naively optimistic, but I would think that training a new generation of physicians to use these tools would mean teaching them that professional judgment isn't a matter of letting your gut feeling second guess these formal models - it would be based on taking into account evidence that may not be incorporated into the formal model.

I very much agree with you (and the comments below) that PA's, nurses and nurse practitioners should be given more of a role in care, primary care especially. But is it really the case that they do better mainly because their lack of more extensive knowledge prevents them from second guessing algorithms, or is it because they are the ones who, more than physicians, actually implement treatments, build a trusting relationship with patients, and follow the patient's progress in more closer detail?

Getting the patient to stick to a treatment plan and be open about concerns and problems is important for success, and a non-overscheduled nurse practitioner who spends more time with the patient is more likely to get a patient to stick with the treatment plan and report any signs of trouble.

There is a role for formal models in medicine, but I'm not convinced that, in complex cases, they do what I thought Ayers was saying they do. Take chest pain - a patient shows up at the ER with chest pain. There can be fairly obvious cases like a heart attack, which a formal model might automatically pick out, but it quickly gets more complex from there, and I'm skeptical that all of the relevant variables have been quantified well enough to make a reliable model in non-heart-attack cases.

I understood Ayres to be arguing that in a case like this, your patient with chest pain would report to the ER, a nurse would collect the relevant information (including the results of some lab tests), and out pops a diagnosis with a confidence score. For heart attacks we might be able to do that, but once that's ruled out, I don't think the state-of-the-art is anywhere close to producing a reliable diagnosis.

The goal should not be to eliminate the role of doctors, et al., entirely by machines but to make their contribution to societal health more macroeconomically efficient and quite possibly to make their work more fulfilling at the same time. The trick is to replace those parts of the process that humans do poorly. Part of this is fast and accurate searching and testing of diagnostic options (this is more or less what is being talked about in the article). But this is only vaguely defined and overly simplistic in any case.

From an economics limits point of view we are have already reached both the upper and lower bounds of economic scaling for the medical profession. On the lower bound of individual work we can't squeeze more performance per hour of work out of doctors without pushing accidental death rates to very noticeable levels (you are already more likely to die from accidental death by prescribed medicine or medical treatment than traffic accident in a car). There are only some many hours (2000 hours = 8 hours/day @ 50 weeks a year) in a year any person can work and still productively deliver full value. There are only some many patients that can be seen per hour and still deliver value as an individual.

A standard technique to extend this limit is to create hierarchies of descending skill. This sets the upper-bound for human-delivered value. Lawyers and accountants use this in partnerships. The HMO structure is the medical version of this.

It's the lack of fungibility in professional services that ultimately limits how much this structure scales - and it's is the scaling solution of "last resort" for knowledge workers short of cutting humans out of the loop somehow. The fact that we are not getting medical value (and thus have a "healthcare crisis") from this very system is evidence we've hit the upper bound as well.

Using machines is how the same limits were transcended prior to the industrial revolution when the bottleneck was how much a single craftsman could deliver; the industrial revolution took over those bottleneck tasks. There are still craftsmen today but most are aided by the benefits of the industrial revolution and all are specialized is some way that involves not directly competing with what machines do better. Today with this idea for doctors it's computers, software and new testing equipment instead of looms and steam engines.

The primary process steps that humans have problems with are related to fatigue and attention. In terms of health and medicine this encompasses the surveillance phases of preventative, chronic and maintenance medicine. In each of these there is a need for medically-aware vigilance that would normally enable early cost-saving detection of symptoms and that would be prohibitively expensive to do with people: certainly doctors, even lower skilled medical and dubiously with the patient given medically-directed education. In both cases simple humans limits of fatigue and attention work against the efficacy of these.

There are studies that claim that preventative medical does work well but from what I've seen there is a central flaw in these. The physics says it should always be better and cheaper to detect problems early (as long as you believe the body works by cause-and-effect rather than magic). But this is as long as you can detect the changes. Most studies I've seen presume one or two visits to the doctor per year as "surveillance" for prevention. The problem is that more is prohibitively expensive but this number sample points per unit time is probably almost meaningless in terms of measurement noise for all but the most dominant pre-disease changes. If you could measure more often, the noise floor of the measurement can effectively be lower. For example if you could measure a key parameter every day you'd drop measurement noise floor by a factor of 20 for that parameter. Recent evidence of scale-free distributions in metabolic networks would imply that you can apply an 80-20 rule to what to measure: 80% of metabolic operation involve 20% of the metabolic components (enzymes, products, etc.) so you can enormous diagnostic mileage from measuring only dozens of parameters instead of millions. Since these 20% are interconnected you get extra information about one when measuring another and it's the early failures of the interconnected system that you're interested in anyway.

Economics dictates that automation is the only avenue to have sample rates this high and to measure multiple parameters of interest. And it's the body that will dictate which to measure, not what is cheapest to measure. It must be affordable by anyone and be cheap to operate. Say a hand-sized device costing $100 per month to operate and maybe as much as $500 at initial purchase would seem to be a reasonable target price. This device would ideally be non-invasive but that might not be possible initially - blood samples might be required for some parameters but those might not have to be daily - maybe weekly. On the other hand, the fact that diabetics can self-administer single or even multiple blood tests daily is proof this can be done even with blood samples.

There is the possibility that extremely sensitive gene arrays could allow single point measurement detection of pre-disease states (using blood samples) but from what I personally know about the company holding most of the patents in this area (I used to work there), innovation toward such low cost system is not a goal in any way, shape or form and won't be happening from them or others while their patents are in force in any case. After that? Let's just say that rust never sleeps but it will take a while to get there - longer than we have time for.

So what to do with all this data collected? No, we do not send it to some central computer to process! Creating a new bureaucracy of inefficiency is not what's needed here. And we also need to move toward more individual privacy in this country, not away from it. No. Instead the computation should be distributed because being tethered to your doctor (or hospital or insurance company or government) will only limit mobility and limit adoption. A computer (such as an iPhone or hand calculator) has enough computing power to handle the analysis and diagnosis. The internet can provide updates like it does for desktop computers. But what would such a computing device do?

Keep in mind that the AI program (now it would be called an "expert system") call "Mycin" was created in the 1960s on contemporary hardware of the time and it performed surprisingly well at the time. Newer hardware could to far better as today even the smallest computers in dish washers are literally 1000x faster than what Mycin ran on.

This is not to be all rosy about technology as a savior: such systems have their limits. But the point is to design with those limits in mind just as we are keeping human doctor's limits in mind: i.e. such automated diagnostic tools can be limited and less than perfect if they default to escalation to human doctors. E.g. Computer: "From you symptoms I can't determine a diagnosis with greater than 80% certainty; you must see a doctor to get a better opinion".

This would allow most medical surveillance to be done by individuals where the value delivered by human medical personnel is the worst and allow human medical personnel to deal with the exceptional aspects of medicine where they deliver the most value to patients.

Of course, if individuals have such machines, doctors will have better machines (naturally more expensive but only for escalation). The situations like the TV show "Mystery Diagnosis" really should never be occurring.

There is the question of doctor-patient "relationship" value that this doesn't get addressed by this. I'll simply acknowledge that both some doctors and patients find it valuable and it need to be considered somehow. This value isn't enough to justify avoiding automation, however. That is a certainty.

Becky Jungbauer's picture
There are some medical centers and associations working on the problem like the Institute of Medicine's annual meeting and report on evidence-based medicine, AHRQ's evidence-based practice site - there's even a Foundation for Evidence-Based Medicine.

Congress is getting in on the discussion too. The Comparative Effectiveness Research Act, introduced July 31 by Senate Finance Committee Chair Max Baucus, D-Mont., and Budget Committee Chair Kent Conrad, D-N.D., would create a private, non-profit Health Care Comparative Effectiveness Research Institute governed by a board including HHS agency directors, device and drug makers, clinicians and patients.

Centers for Medicare and Medicaid Services is working on some comparative effectiveness initiatives, like the "coverage with evidence" development - meaning CMS would only cover a therapy if data were  collected prospectively showing evidence that the therapy is effective. One example is warfarin and  potential pharmacogenomic tetsing for appropriate dosing.

Plus, Obama has proposed a comparative effectiveness institute as part of his health care reform to guide reviews and research on the comparative effectiveness of alternative diagnostic and therapeutic interventions. The findings would be incorporated into practice guidelines, standards and other evidence-based decision tools for doctors and patients. McCain's health care reform plan does not mention a comparative effectiveness institute.

Yet if physicians don't adopt the practices, how will any of this help? There's really low adherence, likely due to a majority (about 60 percent, according to a JAMA study in 1999) not knowing the guidelines exist, or knowing what they are. Those numbers have changed a little depending on the condition - anywhere from 17 percent to 71 percent of physicians follow guidelines when managing osteoporosis, while only 25 percent follow guidelines when treating complicated urinary tract infection. Other reasons for non-adherence, the JAMA study says, can include physician attitudes, such as lack of agreement and inertia of previous practice.

If evidence-based medicine, comparative effectiveness, whatever you want to call it helps doctors diagnose and treat patients more effectively, I'm all for it.

As a retired academic clinical pathologist with many years of experience in the application of numerical results to clinical practice, I feel compelled to provide a comment on how numbers appear to be evaluated in medicine. In science,of course, numbers are valued because they provide a degree of certainty about measurement. In medicine, unfortunatly, numbers frequently provide uncertaintity rather than certainty. This is particulary true in regard to a series of values for an anylite taken over a number of of days. Such values change both as a result of the reproducibility of the method of analysis and the course of the illness. The effects of anylitical variation on results is only rarely appreached by most clinicians. Nephrologists are a group clearly understand this problem, in part, because the values which they evaluate are used to determine when patients should be dialyzed. Regretfully, they are one of the few groups of specalists who are aware of this issue. I have often suggested that numerical values be removed from laboratory reports and be replaced by N for normal, an up arrow for an increased value and a down value for a decreased value. Removing numbers from medicine would help to recognize that it is an art rather than a science.

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