As the debate about health care reform rages on, I'm hearing a steady drumbeat of horror stories (from the right) about medical mistakes, insurance screw-ups, and other snafus in existing "single-payer" countries such as Canada and the U.K. These stories serve two purposes: first, they rouse fears about what a single-payer system would mean here in the United States; second, they counteract anecdotes about the failings of our own system.
Nonetheless, they are but anecdotes, and thus may not be considered "fair debate." As we say in science, the plural of "anecdote" is not "data." The problem is that comparing useful data is not easy. Here is a sample attempt, showing the U.S. leading a group of six developed nations (including Australia, Canada, Germany, New Zealand, and the U.K.) in medical errors over the two years to 2005. The most obvious problem with this survey is that it is almost entirely self-reported. Thirty-four percent of Americans reported an error next to thirty percent of Canadians. Maybe Americans are just more likely to report errors, though: such a small difference could easily be attributable to such an effect.
One aspect of single-payer that is particularly troubling is that it is very hard to sue the government. (If you think dealing with a large, profit-driven, lawyer-riddled health insurance company is tough, try the gargantuan federal bureaucracy.) Lower accountability usually results in lower standards. So while these anecdotes should not be extrapolated too literally, there is at least some reason to believe that we would in fact have more errors here if we adopted single-payer. The question is whether some of the errors that we already have due to the complexities of our different payment and care mechanisms would be reduced sufficiently to counteract the loss of accountability. It is impossible to know this without knowing more details about how a single-payer system would be implemented in the U.S., and it might be impossible even then.
At least in the U.S., if they screw up (and you're still alive), there is some recourse. In a single-payer system, there may be none. That should be reason enough not to go that route.