Ben Goldacre, in his sustained critique of the way the pharmaceutical industry and its regulators fall far from the standards of reliable evidence (Bad Pharma), makes an astounding claim (p193 of the paperback, my emphasis):
Trials have been done comparing statins against placebo, and these have shown they save lives rather well. Trials have also compared one statin to another: but these all use cholesterol as a surrogate outcome. Nobody has ever compared the statins against each other to measure which is best at preventing death. This is a truly staggering oversignt when you consider that tens of millions of people have taken these drugs and for many, many years.
There are two pieces of background information that should provide the background required to see why this is an astounding claim.
The first is that statins, designed to reduce cholesterol levels (for a more technical description read the wikipedia entry), are very widely prescribed and make a huge amount of money for the pharmaceutical industry. It has even been suggested that they should be widely used in healthy populations (see BBC news story for background and discussion). They have been the single largest cost category of prescribed drugs in the NHS (2007 BBC story). Total worldwide sales are estimated to exceed $35 billion.
The second is that proxy or surrogate outcomes are not a reliable measure of the effectiveness of a drug. Surrogate outcomes are usually something that is easy or quick to measure (in the case of statins, cholesterol levels). They are used to judge results in trials of drugs because the ultimate goals (the primary outcome) are often harder to measure and take longer to measure (for statins, cardiovascular events and death). The trouble is surrogate outcomes are often misleading. For example, it was long thought that drugs that reduce irregular heart rhythm were good for people who have survived heart attacks as they often have irregular rhythm. But this was shown to be wrong by the famous CAST trial (wikipedia, review article): it turned out that drugs reducing irregular rhythm (the proxy) cause significantly more heart attack deaths (the primary outcome the drugs were intended to prevent).
So, while I would normally just take Ben Goldacre on trust as an expert, this claim is so bold it deserves separate skeptical analysis. He claims there have never been proper trials of one of the biggest classes of drugs that measures what they are intended to achieve.
So has there never been a trial comparing statins using the primary outcome of fewer deaths from cardiovascular events?