In this lecture, Dr. LeLorier explains why an accurate pharmacological basis is crucial when designing a pharmacoepidemiological study. He covers the importance of how a drug is used and highlights the mechanism by which it can produce undesirable side effects. The temporality of the harmful effects is described, as well as the role of pharmacology in defining exposure.
First, the concept of the Pharmacologically Pertinent Period of Observation (PPPO) is explained, using examples of studies that reached incorrect conclusions due to the drug utilisation and/or not taking PPPOs into consideration.
Second, he covers confounding by indication, which is a major challenge for pharmacoepi, and how a solution can be given with pharmacology rather than statistics.
Finally, he discusses causality and the role of pharmacology (or not) in determining whether a causal relationship is present.