Relative risks of age, gender, nationality, smoking, and Helicobacter-pylori-infection in duodenal and gastric ulcer and interactions.

A logistic regression model was applied to assess risk factors and diagnostic predictors in duodenal and gastric ulcer, as well as in unspecific changes of gastric mucosa. In the latter group smoking, epigastric distress, and pain were associated with elevated relative risks. In the gastric ulcer model, increased odds were found for age, German nationality, smoking, and low and high urease activity of antral mucosa. This holds for duodenal ulcer, too; however interactions between complaints, urease activity, and nationality must be considered. In each case odds depend from the composition of the control group. Therapeutic implications have been considered.