Limitations
It is noteworthy that VigiBase collects data on individual case safety
reports and does not contain information on PDE5i consumers who have not
exhibited any adverse events (i.e., controls). Thus, the case-non-case
approach does not estimate the risk of occurrence of a specific ADR,
unlike case-control studies, and alternatively investigates the risk of
ADR reporting through ROR. Data in VigiBase are heterogeneous and
gathered from various sources, including healthcare professionals,
pharmaceutical companies, and patients. Consequently, data is subjected
to reporting bias, and the probability that the suspected adverse event
is drug-related is not the same in all cases. Additionally, incomplete
and unreliable dosing data imposes a significant limitation on our
study, preventing us from performing a dose-response analysis and
investigating whether the occurrence of an ADR in a particular
subpopulation is a consequence of over-dose. Lastly, VigiBase, by
nature, does not provide any information on patients’ comorbidity, which
may predispose one to a specific ADR. Accordingly, certain causal
drug-ADR associations cannot be drawn.