Overview of important methods used for causality assessment of adverse drug events in pharmacovigilance

Introduction: The method of assessing causality between adverse events and suspect drugs is the most challenging task in pharmacovigilance. It requires attentive consideration of both the adverse events and suspect drugs, patient-related factors, and co-suspect drugs and other medical conditions of the patient. Objectives: This review aimed to look for different methods available or reported for causality assessment and give a brief comparison between the methods. Methods: Many pieces of literature were reviewed to present a summary of commonly used important methods for causality assessment. Results: Though different methods were developed to assess causality, no single method has been proved to produce an accurate or authentic ascertainable evaluation of the causal relationship. Conclusions: Hence, causality assessment has become an important step in evaluating drug safety. Due to a lack of uniformity, reliability, and rationality, no single method can be accepted as a standard one across the world.