Several criteria help in establishing causation, often referred to collectively as the Bradford Hill criteria:
Strength of Association: A strong association between the factor and the outcome increases the likelihood of a causal relationship. Consistency: Repeated observations of the association in different studies and populations strengthen the causal inference. Specificity: A cause leads to a specific effect, and not to a wide range of unrelated outcomes. Temporality: The cause must precede the effect in time. Biological Gradient: A dose-response relationship indicates that an increase in the exposure leads to an increase in the risk of the outcome. Plausibility: The association should be biologically plausible based on existing knowledge. Coherence: The association should not seriously conflict with the known facts of the natural history and biology of the disease. Experiment: Experimental evidence, such as randomized controlled trials, can provide strong support for causation. Analogy: Sometimes, causal relationships observed in similar circumstances can support the inference.
