Bradford-Hill criteria
Encyclopedia
The Bradford Hill criteria, otherwise known as Hill's criteria for causation, are a group of minimal conditions necessary to provide adequate evidence of a causal relationship between an incidence and a consequence, established by the English
epidemiologist Sir Austin Bradford Hill
(1897–1991) in 1965.
The list of the criteria is as follows:
in epidemiological study. However, their method of application is debated. For example, using a counterfactual
consideration as the basis for applying each criterion is one perspective. An operational reformulation of the criteria has been recently proposed in the context of evidence based medicine, subdividing them into three categories: direct, mechanistic and parallel evidence, expected to complement each other.
Arguments against the use of Bradford Hill criteria as exclusive considerations in proving causality also exist. Some argue that the basic mechanism of proving causality is not in applying specific criteria - whether those of Bradford Hill or counterfactual argument - but in scientific common sense deduction
. Others also argue that the specific study from which data has been produced is important, and while the Bradford-Hill criteria may be applied to test causality in these scenarios, the study type may rule out deducing or inducing causality, and the criteria are only of use in inferring the best explanation of this data.
Debate over the scope of application of the criteria includes whether they can be applied to social sciences
. The argument proposed in this line of thought is that when considering the motives behind defining causality, the Bradford Hill criteria are important to apply to complex systems such as health sciences because they are useful in prediction models where a consequence is sought; explanation models as to why causation occurred are deduced less easily from Bradford Hill criteria as the instigation of causation, rather than the consequence, is needed for these models.
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
epidemiologist Sir Austin Bradford Hill
Austin Bradford Hill
Sir Austin Bradford Hill FRS , English epidemiologist and statistician, pioneered the randomized clinical trial and, together with Richard Doll, was the first to demonstrate the connection between cigarette smoking and lung cancer...
(1897–1991) in 1965.
The list of the criteria is as follows:
- Strength of association (relative riskRelative riskIn statistics and mathematical epidemiology, relative risk is the risk of an event relative to exposure. Relative risk is a ratio of the probability of the event occurring in the exposed group versus a non-exposed group....
, odds ratioOdds ratioThe odds ratio is a measure of effect size, describing the strength of association or non-independence between two binary data values. It is used as a descriptive statistic, and plays an important role in logistic regression...
) - Consistency
- Specificity
- Temporal relationship (temporality) - not heuristicHeuristicHeuristic refers to experience-based techniques for problem solving, learning, and discovery. Heuristic methods are used to speed up the process of finding a satisfactory solution, where an exhaustive search is impractical...
; factually necessary for cause to precede consequence - Biological gradient (dose-response relationshipDose-response relationshipThe dose-response relationship, or exposure-response relationship, describes the change in effect on an organism caused by differing levels of exposure to a stressor after a certain exposure time...
) - Plausibility (biological plausibilityBiological plausibilityIn epidemiology and biomedicine, the term biological plausibility refers to the proposal of a causal association — a relationship between a putative cause and an outcome — that is consistent with existing biological and medical knowledge....
) - Coherence
- Experiment (reversibility)
- Analogy (consideration of alternate explanations)
Debate in modern epidemiology
Bradford Hill's criteria are still widely accepted in the modern era as a logical structure for investigating and defining causalityCausality
Causality is the relationship between an event and a second event , where the second event is understood as a consequence of the first....
in epidemiological study. However, their method of application is debated. For example, using a counterfactual
Counterfactual
Counterfactual may refer to:* Counterfactual conditional, a grammatical form * Counterfactual subjunctive, grammatical forms which in English are known as the past and pluperfect forms of the subjunctive mood* Counterfactual thinking* Counterfactual history* Alternate history, a literary genre*...
consideration as the basis for applying each criterion is one perspective. An operational reformulation of the criteria has been recently proposed in the context of evidence based medicine, subdividing them into three categories: direct, mechanistic and parallel evidence, expected to complement each other.
Arguments against the use of Bradford Hill criteria as exclusive considerations in proving causality also exist. Some argue that the basic mechanism of proving causality is not in applying specific criteria - whether those of Bradford Hill or counterfactual argument - but in scientific common sense deduction
Deduction
Deduction may refer to:in logic:* Deductive reasoning, inference in which the conclusion is of no greater generality than the premises...
. Others also argue that the specific study from which data has been produced is important, and while the Bradford-Hill criteria may be applied to test causality in these scenarios, the study type may rule out deducing or inducing causality, and the criteria are only of use in inferring the best explanation of this data.
Debate over the scope of application of the criteria includes whether they can be applied to social sciences
Social sciences
Social science is the field of study concerned with society. "Social science" is commonly used as an umbrella term to refer to a plurality of fields outside of the natural sciences usually exclusive of the administrative or managerial sciences...
. The argument proposed in this line of thought is that when considering the motives behind defining causality, the Bradford Hill criteria are important to apply to complex systems such as health sciences because they are useful in prediction models where a consequence is sought; explanation models as to why causation occurred are deduced less easily from Bradford Hill criteria as the instigation of causation, rather than the consequence, is needed for these models.