Liberation From the P Value’s Tyranny
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P-values, next to nuclear weapons, are the worst invention of the 20th century.
—Herman Rubin, Purdue University, 1981
More than a half century ago, the P value was selected as the measuring tool for health care research by administrators. The difficulties generated by statistical hypothesis testing in addition to the constraints it places on cardiovascular trial researchers must now be declared unacceptable by the cardiology research community.
Developed >90 years ago by statistician, Ronald Fisher, while working on a manure experiment in England,1,2 P values have risen to dominate the field of cardiovascular investigation for no other reasons than those of custom and habit. The abuse of P values has become so rampant that the American Statistical Association in 2016 was compelled to provide a consensus statement decrying their misuse.3
Counterpoint, see p 1049
P Value Ascendency
Statistical hypothesis testing and P values were criticized by scientists from the beginning. They thought that its reverse logic—embracing a null hypothesis that one did not think, only to have the data reject it compelling the scientist to accept what one did think—was tortured and unnecessarily complex. P values rose to prominence in health care when grant administrators, journal editors, and Food and Drug Administration officials, overwhelmed by the post–World War II explosion in research, chose the P value instrument to help identify worthy research.4 The P value was not chosen because it had any basis in epidemiology, biology, pathophysiology, or cardiovascular medicine. It was selected because these administrators needed a metric to help them to separate the research wheat from the chaff, and they could see no alternative.
The fledgling clinical trial research community accepted this P value imprimatur, not realizing that this nonmalicious selection portended pernicious consequences. Even though the P value’s sole, small role was to …