Bioethics, healthcare policy, and related issues.
The LA Times reports that 20% of licensed heart, lung, or liver transplant centers in the US do not meet federal guidelines, and that they show higher-than-average death rates. This is a very serious matter, but I think there is reason to suspect that the paper is misinterpreting or over-reacting to the data.
Here is what they say the problem actually consists in:
About a fifth of federally funded transplant programs fail to meet the government’s minimum standards for patient survival or perform too few operations to ensure competency, a Los Angeles Times investigation has found.
The U.S. Centers for Medicare and Medicaid Services has allowed 48 heart, liver and lung transplant centers to continue operating despite sometimes glaring and repeated lapses, the newspaper’s review found. There are 236 approved centers nationwide.
Although many of the substandard programs treat small numbers of patients, their collective failings carry a significant toll.
Consider the latest available statistics, for transplants performed between 2002 and 2004. Nine lung programs failed to meet the minimum Medicare standards for survival, number of surgeries or both.
These hospitals accounted for 21 more deaths than would be expected, based on a government-funded analysis of how all patients fare nationwide within a year of surgery. It is adjusted for the condition of the patients and the organs.
Three dozen heart transplant programs didn’t meet federal standards for survival or volume. They accounted for 43 more deaths than expected.
Altogether, the programs examined by The Times had 71 more patients die than expected within a year of transplant.
Note that, to reach their 20% figure, they lump together the numbers failing either patient-survival standards or guidelines for minimum volume – they then attribute to all such programs a cumulative total of deaths in excess of expectation. But only one of these standards is directly related to patient deaths (the patient survival rate standard, of course). Centers with death rates above the acceptable maximum are, obviously, objectively in violation of a quality standard, but centers with low rates of a particular surgery are merely in violation of a training standard, which may or may not indicate low quality.
The minimum-volume standard is important, it’s true – it is well documented that patient recovery and survival varies directly with the frequency with which the center performs a given surgery, and there is obviously a minimum average frequency necessary for any acceptable overall survival rate. But that figure is only an average, and failing to meet it does not guarantee that a center will be peforming badly on patient outcomes. There is no guarantee either that a death rate which is higher than the national average will also be higher than the maximal accepted standard. (After all, roughly half of all centers have a death rate above the national average, one presumes – but only some of them have an unacceptably high death rate.) Counting centers which violate minimal volume standards and then citing numbers above the “expected” death merely inflates the total number of supposedly substandard clinics while making it sound like they are all suffering excessive deaths, which is likely not true. It is not good to have tranplant clinics operating with low volumes, but there may sometimes be a justification for it, and it does not necessarily mean that those clinics have bad outcomes. A much closer look at the data is needed before any conclusions can be reached in individual cases.
Then there is the matter of the raw numbers of deaths reported: 1-year death rates above the expected numbers by a total of 43 deaths for heart transplants at 36 transplant centers, 21 lung transplants at 9 centers, and (apparently) 7 deaths among liver transplants at 3 centers. In other words, these “substandard” centers each experienced an average of 1 – 2 deaths per year more than expected. The death rates at centers with low volumes of transplants were quite high in some cases, but often simply as a mathematical consequence of the small denominator (one hospital had a one-year death rate of 57%, but in raw terms that was only 4 out of 7 patients). There is no indication in the article whether the “increase” of 1-2 patient deaths per year they’ve noted is statistically significant or not, but it may well not be for at least some of these clinics.
The total of 71 “excess” deaths comes to about 6 – 7% of all 1-year deaths after transplants of these organs:
Annual Transplants: approx. 2,100
1 year death rate: approx. 15 – 20% (or about 315 – 420 of each year’s recipients)
Annual Transplants: approx. 1,000
1 year death rate: approx. 20% (or about 200 of each year’s recipients)
Annual Transplants: approx. 5,000
1 year death rate: approx. 12% (or about 500 – 600 of each year’s recipients)
At the same time, the total number of transplants performed, and the total number of deaths each year, varies by much more than that (see above link). So, if you were asked to statistically distinguish good from bad centers, it would likely require evidence greater than merely a higher death rate.
In the end, then, they seem to have put their fingers on an important problem, but come up short on data that proves that problem is of serious extent. An increase in barely 70 deaths in a one-year period that will see over 8,000 procedures and 1,000 – 1,200 “ordinary” deaths is likely at the margin of statistical significance. It is difficult from that raw-number increase by itself to justify talk about “substandard care”, or to conclude that “The bottom line message is that there are too many programs in the United States that need to be shut down,” as did Dr. Mark L. Barr, president of the International Society for Heart and Lung Transplantation, or that “Congress needs to get together. . . . They need to sit down, they need to gut the system”, as a frustrated patient claimed.
There is good reason to wonder about these transplant programs and their success rates. The data in this article are a good first step toward monitoring and accurately evaluating problem programs. But we need much better data, much more careful analysis, and much clearer and more knowledgeable scientific reporting, to understand the situation carefully. Sadly, the LA Times has not acquitted itself well in this instance.
UPDATE: Fixed one typo and one poor word choice; clarified the last quotation in the second-to-last paragraph.
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