Observational data plays a critical role in epidemiology due to several reasons:
Real-world context: Observational studies provide insights into how diseases and risk factors behave in natural settings, which may differ significantly from controlled environments. Ethical concerns: Some exposures cannot be ethically assigned in experimental studies, such as smoking or radiation exposure. Observational studies allow researchers to study these factors without ethical violations. Long-term effects: Cohort studies, in particular, enable researchers to examine the long-term effects of exposures on health outcomes.
