The National Bureau of Economic Research
NBER Digest OnLine, September 2011
Since the 1980s, people eligible for Medicare have been able to choose between the regular fee-for-service plan, under which the federal government pays a set fee to health care providers for each service provided, and Medicare Advantage (MA), whereby the government pays private health plans a fee for each individual they enroll. Almost one quarter of Medicare beneficiaries are currently enrolled in Medicare Advantage plans.
Paying the same amount for every person enrolled in a health plan encourages plans to enroll low-cost people and to avoid high-cost ones. Because of this, the federal government historically overpaid for MA enrollees relative to their costs in traditional Medicare. So, in 2004 the Medicare program began to adjust its payments to private plans for enrollees health status. As a result, a plan would, for example, receive a higher “risk-adjusted” payment for a recipient with diabetes or heart disease than for an otherwise identical person without these conditions.
In “How Does Risk Selection Respond to Risk Adjustment? Evidence for the Medicare Advantage Program” (NBER Working Paper No. 16977), Jason Brown, Mark Duggan, Ilyana Kuziemko, and William Wollston study individual-level data for 55,000 people in the Medicare Current Beneficiary Survey (MCBS) from the period 1994 to 2006. Prior to risk adjustment, insurers simply had an incentive to enroll individuals with low costs. After risk adjustment, insurers instead had an incentive to enroll individuals with low costs conditional on their medical conditions. The main reason for this is that the risk adjustment formula pays the plans the average cost of the average person in a particular risk category. The authors demonstrate that, because individuals with less costly cases of diabetes and other health conditions enrolled in MA plans after the move to risk adjustment, overpayments to these plans actually increased.
The risk adjustment formula that is used also explains only 11 percent of an individual’s fee-for-service costs in the year after risk is assessed. The formula systematically over-predicts costs for those with below average costs, and systematically under-predicts costs for those with above average costs. The authors find that individuals who are more expensive than the average person to insure are less likely to enroll in Medicare Advantage plans. So on balance, the government ends up paying the average cost for people who, had they stayed in fee-for-service Medicare, would have cost the government much less.
Before risk-adjustment began in 2004, switching from fee-for-service Medicare to Medicare Advantage increased average individual Medicare spending by $1,800. The authors calculate that using risk adjustment formulas on the population that enrolled before 2004 would have reduced Medicare Advantage overpayments by more than $800 a person. But when the reimbursement formula changed, so did the pattern of enrollment in Medicare Advantage plans. After 2004, switching from fee-for-service to Medicare Advantage increased Medicare spending by approximately $3,000 per person. Thus the shift to risk adjustment actually increased Medicare spending.
Although Medicare Advantage plans did enroll people with higher “risk scores” after risk adjustment was instituted, those people still tended to be significantly below the average cost in their risk category. Furthermore, both before and after risk adjustment, MA enrollees in poor health expressed greater dissatisfaction with their medical care relative to their counterparts in traditional Medicare. This pattern suggests that MA plans invest more resources in their relatively healthy enrollees, perhaps to differentially retain them. Thus the authors conclude that the Medicare Advantage program both increased total Medicare spending and transferred Medicare resources from the relatively sick to the relatively healthy, and that risk-adjustment was not able to address either of these problems.
http://www.nber.org/digest/sep11/w16977.html
And…
How does Risk Selection Respond to Risk Adjustment? Evidence from the Medicare Advantage Program
By Jason Brown, Mark Duggan, Ilyana Kuziemko, William Woolston
NBER Working Paper No. 16977, April 2011
We close by returning to the potential distributional consequences of our results. Regardless of how the surplus described above is split, the MA program appears to expand the cost of Medicare while also transferring relative expenditures from the FFS population toward the financing of care for the MA population. As those switching into MA have, throughout the sample period, lower baseline costs and better self-reported health than do those remaining in FFS, the MA program transfers Medicare expenditure to those who likely have less need for it.
Moreover, as we show in Section 7, the gradient of satisfaction with one’s health care is a more positive function of self-reported health for MA enrollees than FFS enrollees, consistent with MA plans treating their healthier (and thus more profitable) enrollees better so as to differentially retain them. Indeed, exit rates out of MA plans are differentially higher among those in poor health. Therefore, the MA program appears not only to transfer aggregate Medicare expenditures from the relatively higher-cost FFS population to the relatively lower-cost MA population, but it seems to effect a similar transfer within the MA population.
These results suggest that governments may wish to take special care in “contracting out” social insurance. Imperfect pricing – whereby the government overpays a private firm relative to the cost and quality of in-house production – is, of course, a potential concern every time governments contract with a private party and has received great attention in the literature (see, for example, Hart et al. 1997). In the case of, say, paving a road, the consequences of imperfect pricing would seem limited to whatever amount the government overpaid. With social insurance programs, however, imperfect pricing can induce private firms to cream-skim, exacerbating the utility consequences of the underlying inequality the program was initially intended to mitigate. At least in the case of Medicare, we find little evidence that risk adjustment has solved this problem.
http://www.nber.org/papers/w16977
Comment:
By Don McCanne, MD
Never underestimate the ability of the private insurance industry to stick it to us. This shocking study on risk adjustment in the Medicare Advantage program should have been a front page story across the nation. It shows us how the private insurers have used risk adjustment – designed to correct their cheating through favorable selection – to further reap their own rewards by upending the adjustments so that they steal even more funds from us!
How could this be? Some history.
Congress was sold on the concept that private insurers could provide higher quality at lower costs than could the traditional, government-run Medicare program. The Medicare + Choice program was established to do this. Even though the plans were able to selectively enroll healthier, lower-cost patients (favorable selection), the concept still was a failure and plans began withdrawing from the markets. They could not fulfill their promise of lower costs for comparable care.
The conservatives would not give up. It was essential that a robust market for private Medicare plans be established as an initial step toward privatizing the entire Medicare program (a concept still very much alive in the Paul Ryan proposal which was approved in the House of Representatives). They wer
e successful in passing legislation that gave private Medicare plans (now Medicare Advantage) a new life by paying them about 13 percent more per beneficiary than it costs to provide care for them in the traditional fee-for-service program.
As is that weren’t enough, the plans continued to selectively enroll healthier, less expensive patients, further expanding their margins. To counter this, risk adjustment was applied to the payment rates. If the plans’ beneficiaries were healthier than average, they would be paid less. If they were subject to adverse selection – enrolling a greater portion of sicker patients – they would be paid more.
Enter this study. Although it is 55 pages of a very heavy read, seriously testing your math skills, the conclusions can be gleaned from the summary and excerpts above. The plans continued to favorably select their patients, not only by enrolling the healthy, but even more by selecting fairly healthy patients that had just a touch of illness that would allow the insurers to move them into intensified diagnostic groups that increased their payments much more than the level of illness would warrant.
The authors explain that firms have been able to decrease “extensive-margin” selection and increase “intensive-margin” selection. These terms might be obscure to us, but what isn’t obscure is that this chicanery on the part of the insurers allowed them to escape the risk adjustments that would have reduced their overpayments from $1,800 to $800 per beneficiary (still an overpayment), and replace it with a $3,000 per person overpayment!
The authors conclude that “governments may wish to take special care in ‘contracting out’ social insurance.” They are far too kind. We need to throw the damn crooks out, fix our traditional Medicare program, and then provide it for everyone.