Trends in peptic ulcer morbidity and mortality in Iceland.

A cohort pattern has been demonstrated for ulcer mortality and perforation, pointing to a role of early life factors, while only a period-related decrease has been observed in elective ulcer surgery, which reflects uncomplicated ulcer. The aim of this article was to study whether the susceptibility to peptic ulcer disease is determined early in life, as reflected in a cohort pattern consistent for all ulcer manifestations. The subjects were all patients treated surgically for peptic ulcer (perforations 1962-1990; bleedings 1971-1990; elective surgery 1971-1990) and all deaths from peptic ulcer (perforations and other ulcer deaths 1951-1989) in Iceland. Age-specific incidence and mortality were analyzed graphically by year of birth (cohort) and by year of event (period). The effects of cohort and period on incidence and mortality were analyzed by Poisson regression. Ulcer perforation and bleeding, operative incidence, and mortality, showed a rise and subsequent fall in successive generations, with the highest risks observed in the subjects born after the turn of the 20(th) century. This was confirmed by statistical analyses showing highly significant cohort effects (P <.001) and no period effects. A cohort pattern was similarly found for elective ulcer surgery (P <.001), as well as a period-related decrease across age groups (P <.001). Ulcer complications, ulcer deaths, and uncomplicated ulcer were particularly common in specific generations carrying a high risk of peptic ulcer throughout their lives. These were the generations with the highest prevalence of H. pylori antibodies, the subjects born after the turn of the century at a time of maximum crowding and poor hygiene in Iceland due to the industrial revolution.