This is a complete anomaly, which is extraordinary really: it's a book written for a popular audience describing how research is done to test whether a treatment works. But beyond that, it also shows how bad research can slip through the net, and what to do about it, as well as showing, crucially, how to identify that bad research, and what constitutes a "fair test" of a treatment. Unlike other books that try to do that (and fail) here there are no simplistic attacks on pharmaceutical companies, or puffing of some quack treatment, it's a genuinely and thoughtfully critical look at the issue of published medical research.