Prevalence and incidence of peptic ulcer disease in a Danish County--a prospective cohort study.

Peptic ulcer prevalence and five year incidence were assessed in a sex and age stratified population sample of 3608 Danish subjects aged 30-60 years. Statements of peptic ulcer disease obtained from questionnaires were scrutinised by reviewing medical records. Life time ulcer prevalence (95% confidence intervals) was 5.6 (4.9-6.4) per cent. Male to female prevalence ratio was 2.2:1, and duodenal to gastric ulcer prevalence ratio was 3.8:1. Thirty two participants with no previous history of peptic ulceration developed an ulcer within the observation period resulting in a five year ulcer incidence of 11.3 (7.4-15.2) per 1000 persons at risk with no demonstrable sex difference. The prevalence of duodenal ulcer has declined in Denmark whereas gastric ulcer prevalence in men has increased slightly. A decline in male duodenal ulcer incidence has probably contributed to the low male to female ulcer incidence ratio, implying that women today incur the same risk of developing an ulcer as men. If such trends continue, they will bring about a new era in ulcer epidemiology characterised by equal incidence in men and women and an even distribution of lesions in the stomach and duodenum.