Table 2.

Hill Criteria For Assessing The Causal Role Of H. Pylori On Duodenal Ulcer

Sr. No	Hill Criteria’s	Description
1	Biological plausibility	Biologically plausible explanations for causation exist.18–20
2	Dose response relationship	Eradication of H. pylori infection decreases the incidence of duodenal ulcer and prevents its recurrence.22,35–37,39
3	Strength of association	Strong association.21,28,29
4	Consistency	The association between H. pylori and duodenal ulcer has been consistently demonstrated in a number of different types of epidemiological studies (ecological, case-control, cohort, randomized clinical trial and cross-sectional).
5	Temporality	Proved in epidemiological studies (case-control, cohort, randomized clinical trial)
6	Study design	All types of epidemiological study designs (ecological, case-control, cohort, randomized clinical trial, and cross-sectional).
7	Reversibility	The removal of a possible cause (H. pylori) led to reduction of disease risk.22,35–37,39
8	Specificity of association	No, exposure to H. pylori is also associated with other diseases like gastric ulcer,31,40 gastric cancer,28,41 gastro esophageal reflex disease.25