Establishing a causal relationship between a factor and a health outcome is a complex process. Epidemiologists use several criteria, often summarized by the Bradford Hill Criteria. These include:
Strength of Association: Strong associations are more likely to be causal. Consistency: Similar findings across different studies and populations. Specificity: A specific factor should lead to a specific outcome. Temporality: The cause must precede the effect. Biological Gradient: A dose-response relationship where increasing exposure increases risk. Plausibility: The association should be biologically plausible. Coherence: The association should not conflict with existing knowledge. Experiment: Evidence from experimental studies can support causation. Analogy: Similar factors can be used to draw comparisons.
