Perforated peptic ulcer in Hong Kong and New South Wales.

Direct comparisons of ulcer perforation rates and trends between countries have not been made in the past. Data on hospital admissions for perforated peptic ulcer during 1 January 1979 to 31 December 1985 were collected in Hong Kong (5868 perforations) and New South Wales, Australia (1669 perforations). Age and sex specific rates per 100,000 population were calculated. In Hong Kong, annual duodenal ulcer and gastric ulcer perforation rates were 13-16 and under two per 100,000 population respectively. In New South Wales, the corresponding rates were between three and four and under two per 100,000 population, respectively. The male:female ratios for duodenal ulcer perforation were consistently about 5:1 in Hong Kong and 2:1 in New South Wales, and for gastric ulcer perforation about 2:1 and 1:1, respectively. The incidence of perforation increased with age, and there was a statistically significant rise, over time, in duodenal but not gastric ulcer perforation rates in persons aged over 60 years in New South Wales; similar trends were seen in Hong Kong. Thus duodenal ulcer perforation occurs five times more commonly in Hong Kong than in New South Wales and this is largely accountable for by the higher rates of duodenal ulcer perforation in Chinese than in Australian males. Such geographical differences can best be explained by the occurrence of multiple aetiological mechanisms in ulcer perforation. Furthermore, there appears to be an increased susceptibility and an appreciable rising trend for duodenal ulcer perforation to occur in the elderly.