Several times a month, I edit or review an article that contains two contradictory statements:

[1] The experiment was not pre-registered.

[2] The experiment complies with the Declaration of Helsinki.

Often, the two sentences are back-to-back. The problem is that researchers who make these statements haven’t read the DoH, because otherwise they would have noticed article 35, which mandates pre-registration:

Medical research involving human participants must be registered in a publicly accessible database before recruitment of the first participant.

When I point out the contradiction, researchers either remove the statement about the DoH, or point to an earlier version that doesn’t mention public registration. How convenient!

The same researchers then go on to report an avalanche of p values, making unwarranted claims about the presence or absence of effects. They would make us believe that they carefully thought about and planned 20-40+ inferential tests. And they agonise about these p values ever so close to some arbitrary magic threshold. Yet they forget that without pre-registration, p values are essentially not interpretable. More on this topic in these classic references:

Wagenmakers, Eric-Jan. ‘A Practical Solution to the Pervasive Problems of p Values’. Psychonomic Bulletin & Review14, no. 5 (1 October 2007): 779–804. https://doi.org/10.3758/BF03194105.

Kruschke, John K. ‘Bayesian Estimation Supersedes the t Test’. Journal of Experimental Psychology. General 142, no. 2 (May 2013): 573–603. https://doi.org/10.1037/a0029146.

In sum, most research in humans is unethical, at least according to the DoH, and researchers agonise over p values that cannot be properly interpreted because of lack of pre-registration, and other issues…

UPDATE: article 21, in the latest (2024) version of the declaration, also mentions rigour and avoiding research waste. More on this topic in this video from Darren Dahly: https://statsepi.substack.com/p/the-declaration-of-helsinki-now-says