Schwartz D, Flamant R, Lellouch J (1970)

L’essai thérapeutique chez l‘homme. Paris: Flammarion.
In 1970, the French statisticians Daniel Schwartz, Robert Flamant and Joseph Lellouch drew attention to the different design requirements for explanatory trials (to assess whether a treatment worked under the most favourable circumastnaces) and trials to assess whether treatments actually worked, in practice.

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Translation of the Foreword in Schwartz, Flamand and Lellouch (1970)

“The book ‘Statistical Methods for physicians and biologists’, written by one of us, announced in the Foreword the preparation of additional volumes for specific fields of application. The current work is the first of these.

The previous book, avoiding entirely mathematical proofs as well as ‘prescriptions’, sticking to the essentials for presenting techniques, enabled the reader to practise statistical methodology in different possible fields. In brief, it was a work tool.

The current book is very different. The adaptation of a method to a field of research involves the skill of the researcher, and becomes more difficult to codify.  When this research, in addition, concerns treatments in man, the complexity increases because of ethical and psychological implications. These difficulties alone are enough to make the editing of a textbook designed to describe the ideal conduct of a therapeutic trial something of an adventure. Efforts have meanwhile led to initial efforts and several books, mainly in English-speaking countries, presenting the principles in a simple manner. It is in this spirit that we decided five years ago to write a book for the French-speaking public.

But a new difficulty has emerged: this is that, at the same time, after some twenty years of experience, physicians as well as statisticians have taken stock of some limitations of their methods, noting that trials done in a rigorous way delivered conclusions that were too often ‘true’ but unusable. Modifications, substantial in some respects, have been proposed, in which our team has participated actively, insisting on the importance of defining the problem from the outset. But as the work progressed, preparation of the book became more complicated, and slowed.

Thus, one could choose between two solutions: either rapid and superficial methodological editing in a new breath, or giving an account of methodology which was in the process of being developed, when it had matured and proven – in ten years… We have chosen a third way: to present the methodology in its current state of development.

The result has been, naturally, that the book is imperfect, that it feels incomplete, and that it lacks examples. It mixes classical aspects, known by all specialists throughout the world, with aspects that are our own, and would more logically be presented in a series of original articles than in a textbook, given that they have not yet proven themselves (overall, to explain to the reader, one can separate our personal message from the classic message by saying that the first corresponds to that which will be called the “pragmatic design”, the second as the “explanatory design.”

Translation by Ulrich Tröhler