Overview
Imagine that you are the director of a large cancer society. Your day-to-day duties require you to conduct some research and oversee employees whose job is to compile data and make health recommendations. One morning you sit down with a cup of coffee and toast, and when you open the morning paper you find that one of your society's recommendations—that women between the ages of 40 and 60 receive screening mammography for breast cancer—has made the headline news. An elderly-rights group is suing your society. This group argues that your recommendation unfairly discriminates against the elderly because you have implied that women over the age of 60 should not be screened for breast cancer.
You rush to the office and find that the teams who made the recommendation are already in a heated meeting. They have split into two factions, and each group is now accusing the other of making bad decisions. But did they? You manage to calm everyone down and review the process they used to arrive at their recommendation. You learn that both groups were concerned that recommending mammograms for women over a wider age range might become very costly, thereby jeopardizing screening for women who might benefit from screening mammography the most.
One group argued that it made sense to screen older rather than younger women. Mammography works better in older women, who have less dense breast tissue. Older women, they reasoned, were less likely to have a falsely positive mammogram and therefore would be less likely to suffer unnecessary procedures or surgery. Unnecessary interventions, they noted, place women at risk for surgical complications, are psychologically traumatic, are costly, and may do more harm than good.
The other group argued that it was unwise to actively screen all elderly women with mammography, because women who had breast cancer would die from other natural causes before the cancer had a chance to spread. After all, breast cancer can take more than a decade to kill, and the life expectancy of older people is limited. Therefore, they reasoned, elderly women would be subjected to an uncomfortable and expensive screening test that would have little impact on the length of their lives. Besides, who would want to undergo chemotherapy in the precious remaining years of their lives?
Both factions made arguments based on sound scientific, economic, and social research, but which group's approach would be best for patients? You and your employees decide to conduct a more extensive analysis of the costs and benefits of breast cancer screening and plan to send out a press release to this effect. But where do you start?
You might start by having a team estimate the likelihood that older women will die of breast cancer if they are not screened and have another team estimate the number of women who are likely to have false-positive mammograms at different ages. You might also wish to obtain information on the number of years of life that mammography will save, the quality of life for women who have different stages of breast cancer, and the psychological impact of a positive test result among women who do not in fact have breast cancer (false-positive test results). Because both teams were concerned about the costs of mammography, you may also wish to calculate the cost of screening mammography and the cost of all of the medical care that might be averted by detecting breast cancer at an early stage. Finally, because each team is interested in knowing whether women in both age groups might benefit from mammography, you decide that the costs and health benefits of screening each group should be compared to not screening women at all. If all of these factors were put together in a systematic manner, you would have conducted a cost-effectiveness analysis.
Why Cost-Effectiveness Is Useful
Now let's take a step back and consider why all of this is important in the first place. Certainly you want to know whether mammography is going to lead to net improvements or net declines in health relative to some standard of care. If it's only going to hurt people, we certainly don't want to do it. But if we know it helps, we also want to know whether it is affordable.
What does “affordable” mean when you are talking about human life? Take a moment to imagine what we could do with an infinite amount of money. We could build a huge public transportation system that eliminates car accidents, pollution, and noise. We could use only solar power and switch to 100 percent recycling, eliminating the major remaining sources of pollution; this would greatly reduce environmental carcinogens and oxidizing agents that cause cancer, heart disease, and premature aging. We could completely mechanize industry, eliminating occupational accidents. Finally, we could create a highly advanced health system that provides full MRI body scans and comprehensive laboratory screening tests for everyone in the population to ensure that cancers and other disorders are detected at the earliest possible stage.
As it is, there are very few nations that can even provide safe drinking water to all their citizens. The challenge, then, is to figure out how best to spend the money we have so that the quantity and quality of life can be maximized.
Thus, even if mammography screening for breast cancer is on the whole effective, it is conceivable that the money spent on it could save more lives if it went toward something else. Cost-effectiveness analysis (CEA) helps determine how to maximize the quality and quantity of life in a particular society that is constrained by a particular budget.
We'll get deeper into this later in the book, but let's examine the specifics of the example to illustrate how resource allocation might work. Assume that the U.S. Congress decided to allocate $1 trillion to the competing health projects we mentioned. It could choose public transportation, greatly reducing pollution (a cause of pneumonia, cancer, and heart disease) and motor vehicle accidents (the fifth leading cause of death). It could invest in clean energy, reducing dependence on oil while reducing air pollution. Or it could choose the universal MRI strategy, detecting more tumor-producing cancers, some of which can be cured if detected early. If Congress knew the cost per year of life saved, it would know how to maximize the number of lives saved with the $1 trillion investment.
One thing that might strike some readers as a bit strange about this hypothetical situation is that we are essentially deciding who lives and who dies. If we save the mothers and fathers with cancerous tumors by opting for universal MRI examinations, many sons and daughters will die in car accidents as a result. Behind these numbers are real people affected by whatever decision is ultimately made. The more tangible these lives are made to the decision makers, the more difficult the decision becomes.
As one physician, Paul Farmer, points out, you cannot let a person die in front of you when you know that an effective treatment exists (Farmer, 2004). Is the solution, therefore, to start a medical clinic, even if it comes at the expense of a more effective vaccination campaign? We might know that one intervention saves more lives than the other. However, when the most cost-effective intervention saves lives we will never see—lives that lie abstracted in numbers—it is more difficult to rationalize the choice.
Nevertheless, policymakers must often make abstracted decisions based on data from cost-effectiveness analysis, and these sometimes involve decisions that improve survival for one group at the cost of survival for another. (We'll see an actual example of this later in the book.) These decisions become more abstract when quality-of-life issues are added to the mix of life-and-death issues.
The sad reality is that making decisions based on “gut feelings” leads to more suffering and more death than making decisions based on science. While the US tends to operate on “gut policy,” other rich nations use science to allocate scarce resources. This may partly explain why health and longevity are declining in the US but are increasing in other rich nations.
Elements of Cost-Effectiveness Analysis
Just as a driver really only needs to know about the accelerator, brake, and gearshift before driving a car for the first time, this section provides the basic parts of a cost-effectiveness analysis that you need to have in your head before you can start getting down to business. As we get further into the book, you'll be introduced to more advanced and complex methods that will build on the foundations of earlier chapters.
Health Interventions
A health intervention is a treatment, screening test, or primary prevention technique (for example, vaccinating children to prevent measles). Health interventions typically reduce the incidence rate of disease or its complications, improve the quality of life lived with disease, or improve life expectancy. Most produce some combination of these benefits. The benefits of a health intervention are referred to as outcomes. Health outcomes can assume any form, but the most common health outcomes are big-picture items, such as hospitalizations prevented, illnesses avoided, or deaths averted ...