Should we continue to fund large observational epidemiological studies?

Large epidemiological studies were the Graal of public health researchers notably after the WWII mainly because of the irruption of computers. Big is beautiful and bigger is more beautiful.Indeed the magnitude of studies hid biases of the findings and much more of their interpretations.


The major part of those studies is observational. Let us recall what are the limits and biases of observation of a large number of humans.

Causality: the rules.