Does public health work?

As public health staff in England move from the NHS to local authorities, we expect councillors and their chief executives to question the value of all those highly trained, expensive specialists. Never easy to show that you make a difference so I was interested in this brave attempt. Unfortunately the data turn out to be a lot more messy than I had hoped, and I think some of the authors' assertions are too strong. But we should applaud the research concept.

Part of the problem is that they used two different sources of data for information on food poisoning. Note that one includes viral outbreaks and the other does not.