To be able to decide in favour of one treatment method over another, it is not enough for the method to yield better results the difference found must also exceed a certain limit, the extent of which is a function of the number of observations. In 1840, for example, Jules Gavarret noted that:Īverage mortality, as provided by statistics, is never the exact and strict translation of the influence of the test medication but approaches it all the more as the number of observations increases.Ī therapeutic law can never be absolute its applications can always oscillate between certain limits which are all the narrower, the more the collected observations are multiplied, and which can be determined with the aid of the numbers constituting the statistics that have provided the law. From the middle of the 19 th century onwards, the importance of the ‘law of large numbers’ became acknowledged increasingly within medical research.

Some medical researchers and commentators on tests of medical treatments recognised more than two centuries ago that conclusions about the effects of treatments should be based on adequate numbers of people ( Tröhler 2010). Recognition of the need for adequate numbers of observations in clinical trials

Goodman, data dredged outcomes are ok