‘Prevention Doesn’t Pay?’ Logic Explodes This Myth


When I was young, I loved mythology. I read the Greeks and the Romans, and especially liked the Norse. Thor and Loki battling the giants — great stuff. It was a natural transition to science fiction and fantasy as a teenager. Go, Frodo!

I’ve kept my interest in mythology and fantasy. It was superb preparation for a career in medicine, a field as fraught with mythology as any could be. Much of what I see in the media about managed care would fit right into any issue of Amazing Stories.

One fable goes like this: “Health plans have no interest in preventive medicine, since the return on investment takes years, and the tenure of members is too short to see any benefit.”

Listeners nod at this scrap of folk wisdom as if it were incontestable: Let’s move on to talk about the stock market. But it simply ain’t so.

First of all, most health plans put their money where their mouths are, spending huge bucks on preventive care. Where does the notion come from that there is “no interest?” Believe me, dollars are a terrific measure of interest.

“Prisoner’s Dilemma”

More fundamentally, there is a tangible return on investment when health plans support preventive medicine. This is easily demonstrated through a little piece of structured reasoning known as, “The Prisoner’s Dilemma.”

The Prisoner’s Dilemma was originally proposed in 1950 by Flood and Drescher, and restated by Albert Tucker in 1951. It can be presented in a form like this:

The police arrest two criminals. The prosecutor puts them in separate rooms and offers each this bargain: “If you confess and give evidence against your partner, you will go free, and your partner will be sentenced to five years in jail. If both you and your partner confess, you will each be sentenced to two years. If neither of you confesses, there is enough evidence to convict you both for one year.”

What is the “smart” thing to do if I’m the prisoner? By simple computation of the logic matrix, there is one clearly best strategy: Confess. Surprising? Here’s the proof.

If my partner confesses, I have two alternatives: Confess and go to jail for two years, or be silent and go to jail for five years. If my partner is silent, I have two alternatives: Confess and go free, or be silent and go to jail for one year.

In either case, confessing yields the better outcome. It is crucial to see that this isn’t the optimal outcome, which only occurs in the least probable scenario when both criminals act against their own logical interests. In the real world, the probable thing is what is going to occur most of the time.

This model, with different contingencies and weights, can be applied to an array of moral problems. In a different variation, it nicely fits the question, “What attitude should health plans take toward preventive care?”

Prevention might pay off in the long term, or in the short term, or not at all. Whatever the case, the plan’s best bet is to cover prevention.

The don’t-cover-prevention myth rests on the assumption that preventive care only benefits members after they leave a health plan. If this were true, every payer’s best strategy would be to exclude coverage, and operate on a level playing field where nobody gets preventive care.

The myth says that this would reduce plans’ short-term costs, since most of the increased morbidity occurs among people who are over 65, when nobody has to pay for anything. To tell the myth another way, “It profits a plan not at all to pay for prevention, as this will only benefit other plans and Medicare.”

Let’s analyze this strategy in light of the Prisoner’s Dilemma. It’s a bet on the least probable scenario. Whether prevention works or not, if nobody covers it, all payers enjoy short-term savings.

However, if prevention is effective in any time frame, cutting back means patients eventually get sicker, health costs go higher, and doctors’ and hospitals’ incomes soar. Is this in payers’ interests?

What if only one plan pays for prevention and the others don’t? The myth would say, “Then the other plans and Medicare get the benefit of the first plan’s investment for free.”

That’s silly

If prevention pays off (even only in the long term), the nonpaying plans would only enjoy preventive dividends on the members they inherit from the paying plan. They would lose the advantage on members who have stayed with them.

It would make more sense to invest in prevention themselves. If members stick with any plan long enough to return a preventive dividend, that plan benefits. If they go to other plans, nothing is lost if they are replaced by members who have been getting preventive benefits. Therefore, it is in every plan’s interest to bet on preventive care and to encourage all other plans to do the same.

By this analysis, the highest yield strategy is when all plans cover prevention, even if it only works in the long term. If prevention works, you win. If it doesn’t work, you don’t lose. There still may be market reasons to cover what the community expects. The only real risk is if prevention doesn’t work at all, and you’re the only one paying for it.

Hypothetically, a plan could lose big time, if it were willing to sacrifice its own preventive dividend just to spite other plans. This strategy is self-defeating for several reasons.

First, there is a market value in preventive care, since it tends to attract and retain a healthier segment of the population.

Second, a certain number of members do stick with their plan for several years. Without preventive care, this group becomes a cost liability that smarter plans have managed.

Third, such a strategy also depends on a plan never having to cover retirees or offer Medicare supplemental or risk products.

Most of all, the prevention myth depends on there being zero return on any preventive program within the first couple of years. As logic shows, it would still be worth paying for prevention, even if this were true.

However, a growing body of research demonstrates that this is wrong. There are substantial data indicating that specific disease management strategies can return improved health outcomes within the initial year.

Myths are fun. But, if you take them literally, you could be headed for disaster. Think about this the next time some consultant tells you how to make wings of wax and fly to the sun.

Michael S. Victoroff, MD, is medical director of Aetna U.S. Healthcare of Colorado, and chairs the committee on medical informatics of the Colorado Medical Society. His opinions are not necessarily those of Aetna U.S. Healthcare, its management, or its employees.

MANAGED CARE September 2001. ©MediMedia USA