Assessing intravitreal anti-VEGF drug safety using real-world data: methodological challenges in observational research

Introduction: It is generally acknowledged that the ocular safety profile of intravitreal anti-VEGF drugs is acceptable, while the burden of systemic safety of these intravitreal agents is still being debated. The evaluation of the systemic safety of these drugs using real-world data (RWD), such as spontaneous reporting systems (SRS), electronic medical records (EMRs) and claims databases has several advantages, including the capture of outcomes among real-world populations over long observation periods. Nevertheless, there is a relatively small body of research exploring the post-marketing safety of these drugs. Areas covered: The aim of this scoping review is to outline and discuss some of the methodological challenges to be faced when investigating the systemic safety of intravitreal anti-VEGF drugs using different sources of RWD. Expert opinion: Such challenges include the selection of the most suitable data source, taking into account how well drug utilization is captured and whether the outcomes and covariates of interest can be captured. The strengths and limitations of some analytic methods that can be used to quantify risk, such as the intention-to-treat approach and the as-treated approach, complement each other, and using these together provides a more balanced analysis.