Crohn's disease and ulcerative colitis: morbidity and mortality.

This study analyzes hospital discharges and deaths from 1971 to 1986 for patients with inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis. The data are based on hospital morbidity and mortality statistics provided to Statistics Canada by the provinces. For Crohn's disease, age-standardized rates per 100,000 population for hospital discharges increased by 148% for males and by 192% for females over the study period. In 1986, the rate for females was 48% higher than the rate for males. For both males and females, age-specific discharge rates were highest in the 20-24 age group. For ulcerative colitis, male age-standardized discharge rates decreased by 17% from 1971 to 1977, and then increased by 41% from 1977 to 1986. For females, the rates decreased by 18% from 1971 to 1976, then remained fairly stable from 1976 to 1986. Male and female discharge rates were similar over the study period. For females, rates were highest in the 20-34 age groups; for males, they were highest in the 65 and older age groups. In 1971, rates for both types of IBD were almost the same, but by the end of the study period the rate per 100,000 population for Crohn's disease was 34 for females and 23 for males, while for ulcerative colitis the rates were 13 for females and 14 for males. During the 16-year study period, cause of death data showed 556 deaths directly attributed to Crohn's disease and 761 deaths attributed to ulcerative colitis. The under 45 age group accounted for 25% of deaths due to Crohn's disease and for 17% of deaths due to ulcerative colitis. The time trends for IBD hospital discharge rates in Canada closely parallel the findings of hospital discharge rates in the United States and England-Wales. A comparison with epidemiological population surveys strongly suggests that increased discharge rates are due mostly to increases in incidence and prevalence of IBD in the general population.