An Analysis of the Increase in Lung Cancer in Canada

Lung cancer mortality in Canada over the period 1936-1964 is reviewed and a forecast is presented of future trends in the death rates, based on cohort analyses. Since 1936 the annual increases in mortality have been greater among individuals over 65 years of age, but in this group no single five-year age-group has contributed the major part to the general increase. Cohort analyses show (a) that the rate of increase of lung cancer has been much slower in generations born after 1906, (b) that the actual death rate will rise more slowly in the future, and (c) that the death rate may become stable within 15 years.     

Barbiturate Mortality as an Index of Barbiturate Use,Canada, 1950-1963

Changes in Canadian rates of mortality from barbiturates are examined, and their relation to barbiturate use in the general population is discussed. While the number of deaths attributed to barbiturates quadrupled, from 63 in 1950 to 232 in 1963, there has been a concomitant decrease in the number of deaths from inhalation of utility gas.Combined rates for deaths from utility gas and barbiturates declined steadily for most age groups between 1950-52, 1955-57, and 1959-63. It is possible that the increased mortality from barbiturates represents a change in fashion in regard to method of suicide. Changed mortality from barbiturates is not a valid measure of the extent to which consumption of barbiturates has increased in the Canadian population.     

Mortality rates among patients with end-stage renal disease in Canada, 1981-86.

We assessed the mortality rates by age, sex, race, blood type, primary diagnosis, treatment and transplantation history of 8432 patients in Canada for whom end-stage renal disease (ESRD) was diagnosed between 1981 and 1986. Significant differences in the probability of dying were found between those with and without diabetes mellitus, between those who had received a renal transplant and those who had not, between white and nonwhite patients and between various age groups. The mortality rates of the ESRD patients were at least three times higher than those of the general Canadian population. Primary diagnosis and treatment were significantly associated with the risk of dying among the ESRD patients. For those who had received a transplant, the length of time spent waiting for a transplant was positively associated with the risk of death from ESRD. Patients who had received peritoneal dialysis before transplantation had a higher risk of death than those who had received either hemodialysis (risk ratio 1.3) or transplantation (risk ratio 3.2) as the first treatment. No significant differences were found in the cause of death between those who had received peritoneal dialysis and those who had received hemodialysis. Almost half of the deaths among women without diabetes who had received a transplant were due to infection.     

Mortality from cardiovascular diseases in the Semipalatinsk historical cohort, 1960-1999, and its relationship to radiation exposure

The data on risk of mortality from cardiovascular disease due to radiation exposure at low or medium doses are inconsistent. This paper reports an analysis of the Semipalatinsk historical cohort exposed to radioactive fallout from nuclear testing in the vicinity of the Semipalatinsk Nuclear Test Site, Kazakhstan. The cohort study, which includes 19,545 persons of exposed and comparison villages in the Semipalatinsk region, had been set up in the 1960s and comprises 582,656 person-years of follow-up between 1960 and 1999. A dosimetric approach developed by the U.S. National Cancer Institute (NCI) has been used. Radiation dose estimates in this cohort range from 0 to 630 mGy (whole-body external). Overall, the exposed population showed a high mortality from cardiovascular disease. Rates of mortality from cardiovascular disease in the exposed group substantially exceeded those of the comparison group. Dose-response analyses were conducted for both the entire cohort and the exposed group only. A dose-response relationship that was found when analyzing the entire cohort could be explained completely by differences between the baseline rates in exposed and unexposed groups. When taking this difference into account, no statistically significant dose-response relationship for all cardiovascular disease, for heart disease, or for stroke was found. Our results suggest that within this population and at the level of doses estimated, there is no detectable risk of radiation-related mortality from cardiovascular disease.