A commentator brings up risk factor epidemiology, and while I’m not sure the following very short commentary* by Aris Spanos and I directly deals with his query, Greenland happens to mention Popper, and it might be of interest: “When Can Risk-Factor Epidemiology Provide Reliable Tests?”
Here’s the abstract:
Can we obtain interesting and valuable knowledge from observed associations of the sort described by Greenland and colleagues in their paper on risk factor epidemiology? Greenland argues “yes,” and we agree. However, the really important and difficult questions are when and why. Answering these questions demands a clear understanding of the problems involved when going from observed associations of risk factors to causal hypotheses that account for them. Two main problems are that 1) the observed associations could fail to be genuine; and 2) even if they are genuine, there are many competing causal inferences that can account for them. Although Greenland’s focus is on the latter, both are equally important, and progress here hinges on disentangling the two to a much greater extent than is typically recognized.
* We were commenting on “The Value of Risk-Factor (“Black-Box”) Epidemiology” by Greenland, Sander; Gago-Dominguez, Manuela; Castelao, Jose Esteban full citation & abstract can be found at the link above.