There was a time, I am told, when there were bookies in London who would take bets on the outcome of any kind of event. What if they were asked to accept a wager on the long-term (10 years or so) success of the American health reform legislation in controlling costs?  And if they said yes, then what kind of odds would they give?

The answer might be that, being Brits, they had heard about the legislation but didn’t know the details. Where could they look for information? With that in hand they could treat health reform as a kind of horse race. What kind of track record did similar legislation have in the past have? Would a Republican-dominated Congress in the near future (a stand in for the jockey) change the odds? And would the background dynamic of physician practices, technological developments and intensity patterns, and patient demands effect the outcome in some unforeseen ways (the state of the track)?

An obvious starting point for information would be the Congressional Budget Office, which has projected that the Patient Protection and Affordable Care Act will result in a small deficit reduction over the next decade. The Office of the Actuary of the Center for Medicare and Medicaid Services has projected a slight increase in medical costs over the same period, but still a reduction in the deficit.

More recently, other analysts have come to similarly optimistic conclusions. David Cutler and colleagues in a Commonwealth Fund report assess the impact of the legislation on health care costs for the whole health care system, not just the federal government as the above cited studies did. They project a saving of $185 billion between now and 2019, and overall expenditures in that year of $4.3 trillion, down from the $4.6 trillion projected earlier. Annual Medicare cost increases, they contend, will rise from $425 billion in 2009 to $684 in 2019, a significant improvement in comparison with earlier an earlier projected $823 billion. In short, their figures make the reform legislation a clear winner. But they did not speculate who the jockey might be, and assumed the track will not be muddy.

The policy analyst MIT’s Jonathan Gruber is on the whole optimistic, but he introduces a cautionary note. There is great uncertainty about how far the legislation will go in slowing cost growth, “mostly because there is such uncertainty in general about how to control the rate of growth in health care costs,” he wrote in the New England Journal of Medicine last month. A possibly muddy track, that is.

A recent Kaiser Health News story serves to underscore Gruber’s point. It reported that health care spending in Utah, often noted for its lower costs and well run medical institutions, has seen a significant increase its Medicare costs in recent years. “Medicare recipients,” it reports, “are receiving certain kinds of surgery more frequently and are admitted for longer periods to intensive care units during their final days.” Moreover, the story notes, a similar trend has been observed in other areas often cited – by Atul Gawande, for instance – as models for their control of costs (even at the Mayo Clinic).

By now the bookie may be a little uncertain. Maybe the sure thing of the Commonwealth report is not so sure after all. And he may be positively befuddled by an article with the catchy title, “Health Overhaul Puts Wallets in ICU,” by Grace-Marie Turner, president of the Galen Institute, an avowedly market-oriented think tank unfriendly to big government programs. Even the CBO’s revised estimate of $115 billion more than it had earlier projected, “that is still based on unrealistically high assumptions about cuts in Medicare and unrealistically low assumptions about the cost of the new law.”

In other words, it sounds like a one-eyed jockey running on a muddy track. Douglas W. Elmendorf, director of the CBO, was not notably more optimistic when he said, in a May 26 presentation, that the health legislation “does not substantially diminish the pressure” of rising health costs.

With all this incompatible information in hand, the bookie might well be nervous. If the Commonwealth report supports a 10-1 favorable odds, and the Gruber study suggests they might be lowered to 8-4, and the Kaiser report to 7-4, and Grace-Marie Turner projecting a sure loser, then 7-6 might be all he would offer. That still makes the legislation a decent bet, but hardly a certain winner. Yet is a far better bet than one that might, had the legislation failed, been placed on the nag of a pre-reform horse, a tested and wanting loser.

Daniel Callahan is editor of the Health Care Cost Monitor. His most recent book is Taming the Beloved Beast How Medical Technology Costs Are Destroying Our Health Care System.