-
Views
-
Cite
Cite
Mika Kivimäki, Archana Singh-Manoux, Jane E Ferrie, G David Batty, Post hoc decision-making in observational epidemiology—is there need for better research standards?, International Journal of Epidemiology, Volume 42, Issue 2, April 2013, Pages 367–370, https://doi.org/10.1093/ije/dyt036
Close - Share Icon Share
Extract
For the purpose of establishing cause and effect, randomized controlled trials (RCTs) are the gold standard. Compared with observational studies, the major advantages of RCTs—assuming the trial is adequately powered and group allocation truly random—include the elimination of the impact of confounding and reverse causation, and blinding to the exposure status which minimizes investigator/participant biases (Figure 1, left panel). A less often acknowledged ‘strength’ is declaration of the hypotheses being tested and definition of primary exposure and outcome measures prior to analysis: integral parts of trial registration.
The fact that a priori hypotheses and pre-defined measures are not required in observational studies (Figure 1, right panel) provides authors with opportunities to ‘recalibrate’ their research questions and exposure definitions during and after the analysis and in response to feedback from reviewers. Such possibilities, combined with the fact that observational studies typically capture an array of exposure measures, undoubtedly promote scientific exploration and hypothesis generation. However, for hypothesis testing it also confers less protection against post hoc or ad hoc decision-making.1
