When I was a medical student, I went to lectures which told me that HRT was going to stop everything from dementia to heart attacks to teeth falling out. I hardly prescribe it now, such are the hazards, especially of breast cancer, and given that the long term benefits are not what we were sold.
Why did the evidence seem to change? Perhaps the evidence was never really there for HRT in the first place. This is rather a frightening thought, because it would illustrate just how badly we can misinterpret the data. Of course, data may not be what it seems, which is why I’d urge a look at this excellent piece in PLOS Medicine. The bottom line is that doctors ghostwriting for pharma has been everywhere. The point is that you don’t know, as a reader, what is promotional and what is not.
One such case is this: a letter to the Times which appeared to be spontaneously uprising from patients’ representatives and charities. It turned out to be a campaign orchestrated by a pharmaceutical company; my complaints have has recently been upheld on all counts. I don’t think we are where we want to be.