A recent news article in Science (2/19/2010, vol. 237, pp. 936-938) reviews the issues concerning breast-cancer screening for women between 40 and 50. What seems clear is that NOBODY involved in this controversy has done even the most rudimentary decision analysis, yet the question is obviously a good one for such analysis.
According to the article, the major issues are these:
1. Many cancers detected by mammograms in younger women will be detected anyway, even without mammograms. Of the cancers detected without mammograms, most will be cured. The upshot is that, while mammograms do detect cancers (and many women who have had cancers cured after detection with mammograms think that the mammograms saved them), they do not reduce deaths from cancer very much.
2. Still, mammograms do prevent cancer deaths. The effect is small, and its size varies from study to study. The lowest figure seems to be that cancer deaths (which are rare anyway) are reduced by 15%. Or, conservatively (it seems), one death is prevented for every 1900 women screened routinely between ages 40 and 50. (The article is a little unclear about this.) Screening at age 50 prevents one death for roughly every 1300 women screened.
3. So why not? The article puts aside the cost. Let's say the cost is $100. This comes to $100 times 1900, which comes to $190,000 to prevent one death. A very good deal if you ask me. (I suspect that standard insurance policies cover treatments that cost $100,000 to save one year of life. Surely prevention of cancer death in a 45-year-old will save many years of life.) So cost does not seem to be the problem.
4. The article also puts aside the increased risk from x-rays from repeated screening. I'll take their word for it that this is a small factor. (Wikipedia agrees, and cites a reference. Someone correct me if I'm wrong.)
5. The big trade-off according to the article is the risk of false positives. And the big problem with false positives is anxiety. Note that a biopsy is typically not immediate after a positive mammogram, so the anxiety can go on for some time, possibly weeks. The article gives a ratio of 5 biopsies for every case of cancer detected, which means that 4 are false positives. If 10% of these cancers would be fatal if undetected, then this means that the risk of a false positive is about 40 times the risk of death from undetected cancer. (I'm guessing at the fatality rate. It may be much lower.)
It is conceivable that some women would rather take the risk of undetected cancer than the much higher risk of anxiety from a false positive. I would think that research is needed that compares the relative utilities of death from cancer and anxiety from false positives. It may turn out that women differ enough so that they differ in the option that would maximize utility for each patient.
It seems likely to me that very few women would have a sufficiently high disutility for anxiety as to tilt the decision toward no screening after age 40. But the research remains to be done.
Again, what strikes me here is the total absence, so far as I can tell, of analysis of this question in terms of expected utility. Why is this idea so distant from even scholarly discourse?
I welcome comments by email, and I may post a follow-up: baron@psych.upenn.edu.
Saturday, February 27, 2010
Friday, January 22, 2010
Troubles understanding health-insurance reform
The health bills passed by the U.S. house and Senate are complex. Some polls suggest that citizens like them a lot better once their provisions are understood. Both bills contain a logical sequence:
1. Prevent insurers from discriminating on the basis of health risks, such as pre-existing conditions.
2. If this were the only change, insurance costs would go up, and low-risk people would drop out, leading to more increases as insurance covered only those at risk, more drop-outs, more increases, and so on. This has happened when compulsory auto-insurance laws have not been fully enforced. Thus, to make sure that this does not happen, we must have a mandate. And that means a penalty for not having insurance.
3. But the cost of compulsory insurance would hit the near-poor very hard. (The poor are already covered by Medicaid.) Thus, they need a subsidy.
4. To provide this, we need additional funds, either through taxes on the rich (the House bill) or on expensive employer-provided health insurance (the Senate bill).
In sum, any adequate reform has these four elements:
E - equality of those who are healthy and at risk;
P - a penalty if people do not get insurance;
L - help for low-income people;
T - a tax, or reduction of a tax deduction, to pay for L.
To examine people's understanding of these issues, I gave a questionnaire to a panel of people who do questionnaires on the World Wide Web for Pay. I waited for 90 responses. The panel is typical of the U.S. population in income and education, although most are women, and some are foreign.
After defining "health" and "at risk", I started with a basic description of a full plan, EPLT (for all four elements):
"Insurance companies must treat at-risk and healthy people the same (for example, cannot exclude people with pre-existing conditions or charge them more), people must pay a penalty if they do not have health insurance, the government will help low-income people pay for health insurance, and the government will recover the funds by some combination of increased taxes on those with high incomes and reduced tax deductions for expensive employer-provided health insurance."
Then I presented 7 different modifications of the plan: E, EP, EPL, EL, ELT, L, and LT. Then I presented EPLT again. After each of the 9 plans, I asked the several questions, which I list at the end. All the questions, except those asking for an overall opinion, were introduced with: Compared to the present system, how would this proposal affect each of the following?" (I plan to present more details in a later post.)
The most interesting result was the one for question about effects on "The number of healthy people who have health insurance". For the E proposal alone, which specified, "Insurance companies must treat at-risk and healthy people the same (for example, cannot exclude people with pre-existing conditions or charge them more) AND NO OTHER CHANGES", many subjects thought that the number of healthy people with health insurance would INCREASE (40 thought it would increase, 12 decrease, p=.0001). This is diametrically opposed to the economic argument. That argument requires thinking ahead about how insurance companies will respond to the new regulation, and how consumers will respond to that response. It is like thinking two moves ahead in chess. Work I have done with Ed McCaffery (McCaffery and Baron, 2006) suggest that many people rarely think beyond the primary or intended effect of a policy.
It seems that many of my subjects did think through to the first move, however. When asked about "The overall cost (including insurance) to a healthy person who has insurance now" of E alone, 54 said it would increase and only 9 said it would decrease. Thus, the problem seemed to be in the understanding of the effect of price on demand. As the price goes up, fewer people are willing to pay it.
Conclusion: Opposition to the health proposals is based in part on lack of understanding of the four-step sequence outlined above. People may be sensitive to argument about the need for a mandate to prevent people from dropping out because of higher prices ... and to
keep prices lower by making sure that healthy people stay in the pool.
#################################
All questions:
What do you think of this proposal, compared to the present system:
much worse -- somewhat worse -- not sure --somewhat better -- much better
Compared to the present system, how would this proposal affect each of the following?
The number of healthy people who have health insurance:
fewer -- not sure -- more
The number of at-risk people who have health insurance:
fewer -- not sure -- more
The overall cost (including insurance) to a healthy person who has insurance now:
less -- not sure -- more
The overall cost to a healthy person who do not have insurance now:
less -- not sure -- more
The overall cost (including insurance) to an at-risk person who has insurance now:
less -- not sure -- more
The overall cost to an at-risk person who does not have insurance now:
less -- not sure -- more
The cost to taxpayers who already have insurance, including workers who already have insurance through their employers:
less -- not sure -- more
The cost to a person with lower income:
less -- not sure -- more
The U.S. government's budget deficit:
lower -- not sure -- higher
Now that you have considered all these effects, what do you think of this proposal, compared to the present system:
much worse -- somewhat worse -- not sure -- somewhat better -- much better
Reference:
McCaffery, E. J., & Baron J. (2006). Isolation effects and the neglect of indirect effects of fiscal policies. Journal of Behavioral Decision
Making, 19, 1–14.
1. Prevent insurers from discriminating on the basis of health risks, such as pre-existing conditions.
2. If this were the only change, insurance costs would go up, and low-risk people would drop out, leading to more increases as insurance covered only those at risk, more drop-outs, more increases, and so on. This has happened when compulsory auto-insurance laws have not been fully enforced. Thus, to make sure that this does not happen, we must have a mandate. And that means a penalty for not having insurance.
3. But the cost of compulsory insurance would hit the near-poor very hard. (The poor are already covered by Medicaid.) Thus, they need a subsidy.
4. To provide this, we need additional funds, either through taxes on the rich (the House bill) or on expensive employer-provided health insurance (the Senate bill).
In sum, any adequate reform has these four elements:
E - equality of those who are healthy and at risk;
P - a penalty if people do not get insurance;
L - help for low-income people;
T - a tax, or reduction of a tax deduction, to pay for L.
To examine people's understanding of these issues, I gave a questionnaire to a panel of people who do questionnaires on the World Wide Web for Pay. I waited for 90 responses. The panel is typical of the U.S. population in income and education, although most are women, and some are foreign.
After defining "health" and "at risk", I started with a basic description of a full plan, EPLT (for all four elements):
"Insurance companies must treat at-risk and healthy people the same (for example, cannot exclude people with pre-existing conditions or charge them more), people must pay a penalty if they do not have health insurance, the government will help low-income people pay for health insurance, and the government will recover the funds by some combination of increased taxes on those with high incomes and reduced tax deductions for expensive employer-provided health insurance."
Then I presented 7 different modifications of the plan: E, EP, EPL, EL, ELT, L, and LT. Then I presented EPLT again. After each of the 9 plans, I asked the several questions, which I list at the end. All the questions, except those asking for an overall opinion, were introduced with: Compared to the present system, how would this proposal affect each of the following?" (I plan to present more details in a later post.)
The most interesting result was the one for question about effects on "The number of healthy people who have health insurance". For the E proposal alone, which specified, "Insurance companies must treat at-risk and healthy people the same (for example, cannot exclude people with pre-existing conditions or charge them more) AND NO OTHER CHANGES", many subjects thought that the number of healthy people with health insurance would INCREASE (40 thought it would increase, 12 decrease, p=.0001). This is diametrically opposed to the economic argument. That argument requires thinking ahead about how insurance companies will respond to the new regulation, and how consumers will respond to that response. It is like thinking two moves ahead in chess. Work I have done with Ed McCaffery (McCaffery and Baron, 2006) suggest that many people rarely think beyond the primary or intended effect of a policy.
It seems that many of my subjects did think through to the first move, however. When asked about "The overall cost (including insurance) to a healthy person who has insurance now" of E alone, 54 said it would increase and only 9 said it would decrease. Thus, the problem seemed to be in the understanding of the effect of price on demand. As the price goes up, fewer people are willing to pay it.
Conclusion: Opposition to the health proposals is based in part on lack of understanding of the four-step sequence outlined above. People may be sensitive to argument about the need for a mandate to prevent people from dropping out because of higher prices ... and to
keep prices lower by making sure that healthy people stay in the pool.
#################################
All questions:
What do you think of this proposal, compared to the present system:
much worse -- somewhat worse -- not sure --somewhat better -- much better
Compared to the present system, how would this proposal affect each of the following?
The number of healthy people who have health insurance:
fewer -- not sure -- more
The number of at-risk people who have health insurance:
fewer -- not sure -- more
The overall cost (including insurance) to a healthy person who has insurance now:
less -- not sure -- more
The overall cost to a healthy person who do not have insurance now:
less -- not sure -- more
The overall cost (including insurance) to an at-risk person who has insurance now:
less -- not sure -- more
The overall cost to an at-risk person who does not have insurance now:
less -- not sure -- more
The cost to taxpayers who already have insurance, including workers who already have insurance through their employers:
less -- not sure -- more
The cost to a person with lower income:
less -- not sure -- more
The U.S. government's budget deficit:
lower -- not sure -- higher
Now that you have considered all these effects, what do you think of this proposal, compared to the present system:
much worse -- somewhat worse -- not sure -- somewhat better -- much better
Reference:
McCaffery, E. J., & Baron J. (2006). Isolation effects and the neglect of indirect effects of fiscal policies. Journal of Behavioral Decision
Making, 19, 1–14.
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