One exception to that was the Lipid Research Clinics Coronary Primary Prevention Trial that was published in JAMA in 1984 and was heralded as providing the definitive proof that cholesterol reduction was an essential element for prevention of coronary artery disease. In the published pre-trial protocol the researchers set a higher than normal standard for statistical significance stating that they would accept only a p<.01 rather than the usual p<.05. They also specified a two-sided test rather than the less rigorous one-sided test. However the final paper published in 1984 revealed that they had changed these criteria to p<.05 and used the one-sided test. One year later JAMA published a blistering commentary on the study written by Dr. Richard Kronmal, a highly respected biostatistician at the University of Washington. It turned out that the results were not statistically significant using the standards set at the onset of the trial, but barely qualified under the revised statistical parameters. Dr. Kronmal wrote: "The critical aspect of this comment is not the p value that was set prior to the trial or the use of the one-sided test; it is that the observed beneficial effect of cholestyramine now has t he characterization of "statistically significant" (reported as p<.05) and that this is based on a change in criteria that apparently took place after analyzing the data." I have never seen nor heard any response from the people who push cholesterol reduction to this critique of this landmark study.
One exception to that was the Lipid Research Clinics Coronary Primary Prevention Trial that was published in JAMA in 1984 and was heralded as providing the definitive proof that cholesterol reduction was an essential element for prevention of coronary artery disease. In the published pre-trial protocol the researchers set a higher than normal standard for statistical significance stating that they would accept only a p<.01 rather than the usual p<.05. They also specified a two-sided test rather than the less rigorous one-sided test. However the final paper published in 1984 revealed that they had changed these criteria to p<.05 and used the one-sided test. One year later JAMA published a blistering commentary on the study written by Dr. Richard Kronmal, a highly respected biostatistician at the University of Washington. It turned out that the results were not statistically significant using the standards set at the onset of the trial, but barely qualified under the revised statistical parameters. Dr. Kronmal wrote: "The critical aspect of this comment is not the p value that was set prior to the trial or the use of the one-sided test; it is that the observed beneficial effect of cholestyramine now has t he characterization of "statistically significant" (reported as p<.05) and that this is based on a change in criteria that apparently took place after analyzing the data." I have never seen nor heard any response from the people who push cholesterol reduction to this critique of this landmark study.
I think they looked only at the number of events total. Interim looks blinded to treatment are fairly typical.