Safety data is collected through various methods, including clinical trials, post-marketing surveillance, and epidemiological studies. In clinical trials, participants are closely monitored for any adverse effects, which are then systematically recorded and analyzed. Post-marketing surveillance involves monitoring the safety of a product after it has been released to the market, often through spontaneous reporting systems and registries. Epidemiological studies, such as cohort studies and case-control studies, also provide valuable data on the safety of interventions in real-world settings.