The James Lind Library has recently published an article by Doug Altman and Iveta Simera that traces the history of research reporting guidelines and the establishment and development of the EQUATOR Network.

The article states that criticisms of medical research methodological quality can be traced back to 1917, with concerns regarding reporting being highlighted as far back as 1934. Sustained work to address these research issues is however a much more recent phenomenon with the formation of groups developing reporting guidelines and the creation of the EQUATOR Network to raise awareness of all available reporting guidelines and encourage their implementation.

Reference
Altman DG, Simera I (2015). A history of the evolution of guidelines for reporting medical research: the long road to the EQUATOR Network. JLL Bulletin: Commentaries on the history of treatment evaluation
(http://www.jameslindlibrary.org/articles/a-history-of-the-evolution-of-guidelines-for-reporting-medical-research-the-long-road-to-the-equator-network/)