Where in the country are cancer rates highest? The lowest? Are there states that have particularly high rates of schizophrenia and psychosis?

To answer these questions you can’t just pop a thermometer under everyone’s tongue at once. But now there's a group of new federal Web sites that let you become a health care spending analyst. The sites allow you a look at diseases and spending around the country. You can compare states and see patterns over time. You can compare federal trends to particular states or compare states to each other. Some of the information even lets you see patterns at the county level.

The data-centric approach is part of the Obama Administration’s push for open medical information. The data is supposed to help shape public policy and also help consumers find better treatment.

The public policy value is obvious. The “Chronic Conditions Dashboard,” for example, shows state maps of 17 major conditions:

This chart shows the relative frequency of the diseases with a colored map ranging from low incidence in blue to high in red. The frequency chart shows right away that hypertension is a lot more common than cancer or depression. Note that the data is from Medicare and Medicaid, so it is skewed toward older people and lower incomes. You can get more details by looking specifically at the Medicare data or the Medicaid data, or by viewing the charts and maps for each gender. You can also pick specific age groups.

The good news is that you don’t have to work hard at getting the information. Just click on a condition in the chart, and you can see the prevalence in the map. Choose the national rate and any states to include in the chart to compare them.

From this data, I can quickly see that Maryland’s rate of chronic kidney disease is higher than the national rate, while Virginia’s is below it. On the map I can see that the Upper Midwest and Mountain states have lower rates of chronic kidney disease than Florida, Louisiana and Texas.

Like any interface for complicated data, the sites suffer from giving users too many choices and not enough choices at the same time. You can view data for everyone or for just men or for just women. But you can’t see men compared with women at the same time. You can pick age groups, but you can’t compare the prevalence across age groups.

Additional sites unveiled Monday by the Centers for Medicare and Medicaid Services have other slices of data, but none of them work as cleanly. They're clumsy, and they don't link to each other or clearly differentiate why you would want to use one over another. And they're buried among a slew of pages to wade through. Some of the pages took so long to load that I gave up. I know it’s a new effort, but this seems like the work of people who would design an almost impossibly unusable and complex Web site. Oh, wait. It is those guys.

That’s what makes the supposed consumer benefit on this data so unlikely. Related to CMS’s “data-palooza” is a new app being released by MicroStrategy using the data released in April on payments to 880,000 doctors and other medical providers. The Washington Post, however, already lets you search this data, as do Pro Publica and others.

Having it all accessible in an app is more convenient, but the consumer appeal of this information is unclear. Medicare patients are not price-shopping for doctors. Insured patients are more worried about whether a doctor is in their insurance plan than what the doctor charges for a given procedure.

The only consumers who I think might find this valuable are patients seeking care outside their insurance network who are subjected to the unnegotiated, crazy price that is often double what Medicare or insurance companies actually pay. With this app, a shopper who might have to pay can see the real price, like getting the dealer price for a new car. It makes for better negotiating. Real price transparency and real price competition could drastically change the medical system in this country, and these data releases might be a important step in helping consumers. But it’s still a long way from feeling like a real health care shopping venture.