It has a calculator designed to simulate the assessment of hospitals by the government, and shows the possible results and variance by natural chance, even if all hospitals in the sample have 100% the same mortality risk.
What it shows in particular is how the goverment’s assumption that hospitals with death rates 60% worse than the norm are unacceptable is complete nonsense. The calculator shows that as the chance of patient death reduces, the number of hospitals that fall foul of this policy, completely by chance, rises.
It sounds odd, but play with the calculator, and you will see why it is so. Keep this calculator bookmarked, for the next time you see a scare story in the Sunday Mail or News of the World.