The Problem with Preventive Medicine

By Nick Emptage

The passage of the ACA in 2010 has to feel like a high-water mark for proponents of preventive medicine. The Obama health reform essentially makes free preventive care the law of the land, with insurers required to completely cover the cost of a laundry list of interventions intended to avert dreaded chronic illnesses like diabetes, cancer, and cardiovascular disease. The rationale for this policy, often repeated, is that the chronically ill account for 75% of health care spending. Manage their illnesses more effectively through evidence-based treatments and lower-cost non-specialist providers, the argument goes, and you’ll solve health care’s cost crisis, as well as creating a healthier population. As such, by 2014 most insurers will be required to pay for utilization of services like blood pressure, cholesterol, and depression screening, routine cancer screening, obesity and tobacco cessation counseling, and a number of services specific to women and children. The expectation being that a ton of costly chronic illness will never occur as a result.

Unfortunately, there are a few problems with this concept. For one, it directly contradicts the mandate for evidence-based care that most of these folks support: there’s almost no evidence suggesting that these screening interventions have any benefit to patients. A common refrain to this is that engaging patients via preventive screening makes them more conscious of the need for self-management. But this is also unproven: a decade or so ago, “disease management” was a fad that fell short of expectations (as most health policy fads do). In many ways, the push for preventive care is of the “we don’t know what to do, but we have to do something” variety.

But preventive medicine’s problems with comparative effectiveness don’t end there. One of the premises of evidence-based care (like, one of the really, really basic premises) is to avoid providing services with no value to patients. It’s why we care about patient-reported outcomes and using resources efficiently. But providing large volumes of care to asymptomatic, average-risk populations is pretty much guaranteed to waste a ton of resources. If you insist, for example, on regularly screening women for breast cancer without any indication of elevated risk, what you’re mostly doing is inventing a complicated way to keep radiologists busy. Yes, you’ll detect some disease (not all of it will be cancer, of course), and you’ll likely prevent premature death in at least some women. Of course, you’ll also overdiagnose a lot of lesions that will never become malignant, and turn up a ton of false positives. And, importantly, by removing cost considerations from the equation, you’ll be subtly discouraging women from weighing those risks against potential benefits. Interestingly, prevention advocates don’t run from this implication of their work, often embracing the numbers-needed-to-screen statistic in their arguments. Yet implicit in an NNS of, say, 600 is that 599 people receive a worthless intervention. Acute treatments aren’t perfect on numbers-needed either, but they do far better than prevention does, since the populations are smaller.

Unfortunately, the cost rationale for prevention is almost certainly overblown as well. For one thing, the 75% figure is absurd; it includes all the costs of care for people defined as chronically ill, not just the costs of their hospitalizations for uncontrolled disease. For another, the types of analyses that usually establish “cost-effectiveness” don’t really work without evidence of effectiveness. And take it from me: I used to work for a large medical group whose screening recommendations were frequently criticized as heartlessly conservative, and I can tell you that screening programs for large numbers of people are staggeringly expensive. And the patients in our medical group had to cover part of the cost. It’s far from a certainty that providing a wide array of services to a broadly defined population, whose marginal cost of consuming those services is zero, is going to be less costly than acute treatment of a much smaller number of chronically ill patients. Not to mention that preventing some costly conditions earlier on may leave people vulnerable to other costly conditions in later life. I’m thinking specifically of the recent RAND study in the New England Journal of Medicine, which estimated the economic burden of dementia at somewhere between “astronomical” and “economically crippling”. As far as I know, there’s no screening program that can forestall Alzheimer’s disease in early life.

And honestly, I’m surprised by how rarely someone points out that the cost-saving justification for medical interventions is complete nonsense. Since when is “being able to pay for itself” a criterion of value in medical care? Let’s say we have two treatments, A and B; A costs nothing and has no clinical benefits, but receiving it prevents a patient from receiving B, which costs money but treats the patient’s illness effectively. This line of thinking would say that providing A is preferable, since it’s “saved” us the cost of B. This sounds dumb, of course, but that’s because we provide medical care to relieve illness and suffering, not for the purpose of saving money. If the latter is your goal, frankly, you’re better off providing no services at all. If, on the other hand, you recognize the patient’s relief as something of value, simple economics would suggest that you’ll have to exchange something of value to obtain it.

None of this is to say that preventive care is pointless. With an appropriately engaged patient and a clear discussion of their risks and benefits, these interventions can clearly help people to live longer, healthier lives. But consideration of the finer points of the doctor-patient relationship is a far cry from mandating that third parties provide an unlimited quality of services to unlimited numbers of people at no cost. If the end result of this latest effort at health reform is to massively subsidize the provision of services with no real benefit, it’ll be hard to look back on it as a success.