In other situations, initial trials showed a beneficial effect of the intervention which, however, was refuted by a subsequent meta-trial.
This setup ensured that our simulation scenarios are representative of real-world meta-analytic situations, where trials pertaining to a direct comparison typically vary in their sample sizes.
In order to investigate the impact of unequal study sizes, we used simulations, mimicking such realistic conditions rather than situations where trials have implausibly similar sample sizes.
This may not represent the true situation for trials if the registry data are not updated by the researchers.
Similar to the situation with trials, subclinical and minimally symptomatic cases of pancreatitis were less likely to be identified in those studies.
In these situations the trial will stop in a manner independent of its results, and stopping is unlikely to introduce bias in the results.
Similar to the situation in trials, a variable that is a strong prognostic risk factor of the outcome, yet weakly associated with exposure may not be selected for adjustment, yet such omission may result in confounding.
Data for individual steps were averaged, not averages for each trial, to avoid situations where one trial had more complete steps than another.
But, he added, it is hard to judge the situation before trial, "because you don't know what really happened".
"The letter itself was intended to explain the situation and trial a policy that has been successfully adopted by other schools," she added.
