A behind-the-scenes blog about research methods at Pew Research Center. For our latest findings, visit pewresearch.org. Identifying causal relationships from observational data is not easy. Still, ...

This is a preview. Log in through your library . Abstract When the results of a reference (or gold standard) test are missing or not error-free, the accuracy of diagnostic tests is often assessed ...

Longitudinal data in biomedical studies often involve concomitant interventions in addition to the pre-specified repeatedly measured outcome and covariate variables. Since a concomitant intervention ...