Wrong or useless studies in medicine

Although it is a difficult subject we do have at least in medicine a sieve for the worst studies. Observational studies even true are useless. But the preeminence of these studies is still strong because of several factors and among them the data mania and the magic of stat analysis. First, a cohort paid to have one or two "clinical" (actually a huge very unreliable "questionnaire") assessments for 5 years and a lot of "results".  In the same time one or two biological assessments with a huge number of variables. Second, a battery of statistical tests in order to find something like a probability < 0.05. The Graal is so easy.


https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.0020124

https://www.youtube.com/watch?v=MO30X0YlZU0&fbclid=IwAR1Aje3rwCVvYREH832lMwjhoscH46mRxZksTst3mQfxCUpy6MG-nJZ5d1I

https://www.nature.com/news/how-scientists-fool-themselves-and-how-they-can-stop-1.18517?fbclid=IwAR0PpoxHYW8sGXGlsBVHcxsplRPxLn4yDjXp8YEAcgBFFpL2PAQ6r-OtgxA