prev next front |1 |2 |3 |4 |5 |6 |7 |8 |9 |10 |11 |12 |13 |14 |15 |16 |17 |18 |19 |20 |21 |22 |23 |review
To distinguish cause from simple association several factors need to be considered. Hill’s Criteria outline these.

Strength of association: the stronger the association between a putative cause and effect, the more likely there is to be a connection between the two.
Timing: The cause should precede the effect. Never the other way around.
Distribution
: The spatial distribution of the disease should approximate to the spatial distribution of the causal agent.

Gradient
: The response should correlate with the dose; more dose=more effect.
Consistency
: The cause-effect relationship needs to be duplicated in different studies in different places.
Specificity
: People not exposed to the cause should not develop the effect.
Biological plausibility
: the biological activity of the suspected cause should be consistent with its effects.
Experimental models
: animal or other experimental models should demonstrate the effect under experimental conditions.
Preventive trials
: removal of the suspected cause should lead to removal of the effect.

prev next front |1 |2 |3 |4 |5 |6 |7 |8 |9 |10 |11 |12 |13 |14 |15 |16 |17 |18 |19 |20 |21 |22 |23 |review