 Moreover, it is not clear that RCTs are always more reliable than observational studies to answer questions both methods are able to address. Whether or not a study is reliable depends on whether or not confounders and biases have in fact been eliminated, not by which method they have been eliminated. Issues concerning the reliability of a method can be entangled with issues concerning its ability to address the research question the biomedical scientist seeks to answer. Both RCTs and observational studies in the biomedical sciences are typically employed to test rather complex hypotheses about the safety and efficacy of medical interventions. It may well be that some of the issues are more reliably treated by one method and others by the other.