Data from the US Census Bureau and the National Center for Health Statistics suggest that differences in male and female smoking habits between 1920 and 1980 may have contributed to changes in duodenal ulcer mortality sex ratios. An attributable risk analysis suggests that between 43 per cent and 63 per cent of duodenal ulcer mortality for males results from smoking; the comparable figures for females being between 25 per cent and 50 per cent.
