so confounding by other factors should always be considered as an explanation for associations found in an observational study. Explain what is meant by stratification and how this is used to control ...

Observational studies are critical tools in clinical research and public health response, but challenges arise in ensuring ...

A new study comparing multiple and single arterial grafting highlights how physician preference can bias observational data.

Observational studies are subject to CONFOUNDING and BIAS (discussed below), and, as a result, causes are harder to infer; such inferences are almost always dependent on assembling a body of ...