Smoking cessation and mortality trends among two United States populations.

The long-term impact of smoking cessation on mortality is assessed among two U.S. populations: a large cohort of U.S. veterans aged 55-64 at entry and followed from 1954 through 1979 and the NHANES I Epidemiologic Followup Study (NHEFS) cohort of a national sample of U.S. adults aged 55-74 at entry and followed from 1971 through 1992. Direct and indirect survey data indicate that 50-70% of those who were current cigarette smokers at entry had quit smoking during the 19- to 26-year follow-up periods. The impact of smoking cessation on mortality among the cigarette smokers as a whole has been assessed by determining the time trend of the relative risk (RR) of death and 95% confidence interval (CI) for the cigarette smokers compared with never-smokers over the entire follow-up period in both cohorts. The total death rates for the 1954/57 U.S. veteran smokers as a whole (63,159 males) have converged only slightly toward those of never-smokers, from RR = 1.65 (1.58-1.72) during 1954-1959 to RR = 1.61 (1.58-1.63) during 1954-1979. The lung cancer death rates for 1954/57 smokers as a whole have not converged toward those of never-smokers, with RR = 10.89 (7.70-15.41) during 1954-1959 and RR = 11.10 (9.78-12.61) during 1954-1979. The total death rates for the 1971-1975 NHEFS smokers as a whole (694 males and 1116 females) have not converged toward those of never-smokers. For males, RR = 1.92 (1.46-2.52) during 1971-1982 and RR = 1.96 (1.63-2.36) during 1971-1992; for females, RR = 1.79 (1.31-2.46) during 1971-1982 and RR = 1.79 (1.47-2.17) during 1971-1992. The lung cancer death rates have diverged, based on small numbers of deaths. For males, RR = 15.76 (2.06-120.61) during 1971-1982 and RR = 22.20 (5.31-92.92) during 1971-1992; for females, RR = 2.92 (0.57-15.06) during 1971-1982 and RR = 4.74 (1.94-11.59) during 1971-1992. These trends are contrary to the substantial convergence predicted by the death rate trends among U.S. veterans who were former smokers at the beginning of follow-up. While these results confirm that those former smokers who survive for at least 5 years experience death rates that converge toward those of never-smokers, they also indicate that a cohort of cigarette smokers that undergoes substantial cessation experiences a death rate that does not converge toward the death rate of never-smokers. The fact that there has been no convergence for lung cancer is quite surprising, as this is the disease most strongly linked to smoking and smoking cessation and less likely to be influenced by other lifestyle factors. Further investigation is needed for a complete understanding of the impact of smoking cessation.

Smoking cessation and mortality trends among 118,000 Californians, 1960-1997.

We assessed the impact of smoking cessation on subsequent death rates among a cohort of 51,343 men and 66,751 women in California enrolled in late 1959 in the original American Cancer Society (ACS) Cancer Prevention Study (CPS I) and followed for 38 years. We compared the age-adjusted death rate, expressed as deaths per 1,000 person-years, among all subjects who smoked cigarettes in 1959 but who had largely quit as of 1997 with the death rate among never smokers over a 38-year period. The all causes death rate for males decreased from 20.67 during 1960-1969 to 18.68 during 1960-1997 for smokers and decreased from 10.51 to 9.46 for never smokers. The lung cancer death rate for males increased from 1.558 to 1.728 for smokers and increased from 0.127 to 0.133 for never smokers. The all causes death rate for females increased from 9.54 to 10.14 for smokers and decreased from 6.95 to 6.44 for never smokers. The lung cancer death rate for females increased greatly from 0.208 to 0.806 for smokers and increased from 0.094 to 0.116 for never smokers. These results indicate there has been no important decline in either the absolute or relative death rates from all causes and lung cancer for cigarette smokers as a whole compared with never smokers in this large cohort, in spite of a substantial degree of smoking cessation. While cessation clearly reduces the mortality risk among long-term former smokers, the population impact of cessation appears to be less than currently believed.

Vitamin C intake and mortality among a sample of the United States population.

We examined the relation between vitamin C intake and mortality in the First National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-up Study cohort. This cohort is based on a representative sample of 11,348 noninstitutionalized U.S. adults age 25-74 years who were nutritionally examined during 1971-1974 and followed up for mortality (1,809 deaths) through 1984, a median of 10 years. An index of vitamin C intake has been formed from detailed dietary measurements and use of vitamin supplements. The relation of the standardized mortality ratio (SMR) for all causes of death to increasing vitamin C intake is strongly inverse for males and weakly inverse for females. Among those with the highest vitamin C intake, males have an SMR (95% confidence interval) of 0.65 (0.52-0.80) for all causes, 0.78 (0.50-1.17) for all cancers, and 0.58 (0.41-0.78) for all cardiovascular diseases; females have an SMR of 0.90 (0.74-1.09) for all causes, 0.86 (0.55-1.27) for all cancers, and 0.75 (0.55-0.99) for all cardiovascular diseases. Comparisons are made relative to all U.S. whites, for whom the SMR is defined to be 1.00. There is no clear relation for individual cancer sites, except possibly an inverse relation for esophagus and stomach cancer among males. The relation with all causes of death among males remains after adjustment for age, sex, and 10 potentially confounding variables (including cigarette smoking, education, race, and disease history).

Health practices and cancer mortality among active California Mormons.

Religiously active Mormons in California are a nonsmoking population with unusually low risk for cancer. This finding is based on the results of our 1979 questionnaire survey of life-style and the 8-year (1980-1987) follow-up of mortality among 5,231 Mormon high priests and 4,613 wives 25-99 years of age. Our study, which is the first prospective cohort study of Mormons, shows low standardized mortality ratios (SMRs) for this population, relative to those for whites in the general population in the United States, which are defined as 100. The SMRs for males are 47 for all cancers, 52 for cardiovascular diseases, and 47 for all causes; the SMRs for females are 72 for all cancers, 64 for cardiovascular diseases, and 66 for all causes. For middle-aged high priests adhering to three health practices (never smoking cigarettes, engaging in regular physical activity, and getting proper sleep), the SMRs are 34 for all cancers, 14 for cardiovascular diseases, and 22 for all causes. These results have been largely replicated in an active Mormon-like subgroup (white nonsmokers attending church weekly) from a representative sample of residents of Alameda County, CA. Our findings confirm and expand on previous descriptive studies of Mormons and demonstrate how these results can be generalized.

Contralateral breast cancers following treatment for initial breast cancers in women.

The risk of a second primary cancer arising in the contralateral breast following treatment of an initial breast cancer was evaluated for 1,630 women whose first breast cancers were diagnosed and treated at University of California at Los Angeles between 1955 and 1979. Based on follow-up data ranging from 5 to 30 years, the rate of development of nonsimultaneous contralateral breast cancers was slightly in excess of 2.5 per 1,000 person-years at risk. There was no detectably significant difference in the frequency of second primary cancers related to the type of treatment of the first cancers, whether that was surgery, radiation therapy, or surgery plus radiation therapy.

Second primary cancers of the head and neck following treatment of initial primary head and neck cancers.

The risk of a second primary cancer arising in the head and neck, following surgical or radiation treatment of an initial primary cancer in the head and neck, was evaluated for 2,151 patients whose first cancers were diagnosed and treated at UCLA between 1955 and 1979. Based on follow-up data ranging from 5 to 30 years, the rate of development of second cancers of the head and neck was in excess of 2.5 per 1000 person-years at risk. There was no statistically significant difference in the frequency or post-treatment interval of second primary cancers related to the type of treatment of the first cancer, whether that was surgery, radiation therapy, or surgery plus radiation therapy.

The relationship between vitamin C intake, general health practices, and mortality in Alameda County, California.

To evaluate the relation between vitamin C intake and mortality, a prospective follow-up study was carried out among 3,119 noninstitutionalized adult residents of Alameda County, California who had completed a detailed lifestyle questionnaire around the beginning of 1974. During 10 years of follow-up, 276 deaths have been identified. The questionnaire information and mortality data indicate that this sample is fairly representative of the county population and similar to the United States population. There is no important relation between the estimated 1974 vitamin C intake at levels above and below 250 mg per day and subsequent mortality from cancer, circulatory disease, all other causes, or all causes combined. However, there is an inverse relation between combinations of several health habits and total mortality. The health habits include never smoking cigarettes, regular physical activity, moderate or no use of alcohol, 7-8 hours of sleep per day, and maintaining proper weight. The conclusions with regard to vitamin C are limited by the crudeness with which the dietary intake has been estimated and changes in intake over time. Nevertheless, these results are not consistent with any substantial relation between vitamin C intake and subsequent mortality.

Trends in mortality among California physicians after giving up smoking: 1950-79.

A study was conducted to assess how lung cancer and other mortality trends among California physicians had been influenced by the high proportion who had given up smoking since 1950. Several sample surveys indicated that the proportion of California physicians who currently smoked cigarettes had declined dramatically from about 53% in 1950 to about 10% in 1980. During the same period the proportion of other American men who smoked cigarettes had declined only modestly, from about 53% to 38%. Using the 1950 American Medical Directory a cohort of 10 130 California male physicians was established and followed up for mortality till the end of 1979, during which time 5090 died. The information from follow up and death certification was exceptionally good. The standardised mortality ratio for lung cancer among California male physicians relative to American white men declined from 62 in 1950-9 to 30 in 1970-9. The corresponding decline in standardised mortality ratio was from 100 to 63 for other smoking related cancer, from 106 to 71 for ischaemic heart disease, and from 62 to 35 for bronchitis, emphysema, and asthma. The standardised mortality ratio remained relatively constant for other causes of death not strongly related to smoking. The overall ratio declined in all age groups at a rate of about 1% a year. The total death rate among all physicians converged towards the rate among non-smoking physicians. By the end of the study period physicians had a cancer rate and total death rate similar to or less than those among typical United States non-smokers. This "natural experiment" shows that lung cancer became relatively less common on substantial elimination of the primary causal factor, cigarette smoking. Other smoking related diseases also became relatively less common, though factors other than cigarette smoking may have contributed to this change.

Cancer mortality patterns around the San Onofre nuclear power plant, 1960-1978.

Because of the recent concern over possible health effects associated with nuclear power plants, cancer mortality patterns in Southern California have been examined for time periods before the San Onofre nuclear power plant began commercial operation in 1968 and since then. This is one of America's older plants and is surrounded by major population centers in Orange, Riverside and San Diego Counties. Infant mortality rates and age-adjusted mortality rates for leukemia, lung cancer, all cancer, and all causes have been calculated and compared for Orange, Riverside, and San Diego Counties, for California, and for the United States during 1960-1978. In addition, childhood leukemia death rates and clusters have been examined in detail in the communities within 25 miles of San Onofre. The cancer and total mortality rates near San Onofre have remained essentially identical to the corresponding rates in California and United States from 1960 to 1978. There have been no significant radiation releases to the population surrounding the San Onofre plant and the cancer rates show no patterns which have been influenced by the presence of the plant. Although no radiogenic health effects would be expected, these results do provide a means of assessing overall mortality trends in the population.

Mortality among health-conscious elderly Californians.

In an attempt to obtain epidemiologic evidence regarding the mortality rate among vitamin supplement users, a prospective study was made of 479 elderly Californian respondents to a 1974 questionnaire carried in Prevention, a health magazine that advocates vitamin supplement usage. Based on self-reported questionnaire data obtained in 1974 and 1977, this cohort does indeed consume large quantities of vitamin and mineral supplements. In addition, the cohort is quite health conscious and appears to have taken up a "Prevention life-style" in recent years. For instance, these individuals are primarily nonsmokers, although about 50% formerly smoked cigarettes. Most of them eat meat, poultry, or fish but do so in moderation; and they consume only modest amounts of alcohol, whole milk, white bread, salt, and sugar. Their socioeconomic status is somewhat higher than the national average. Because this group differs from the general population in many ways it is difficult to separate the various factors that might influence their health. During 6 years of follow-up, a total of 107 deaths occurred. Based on comparison with 1977 United States whites, the standardized mortality ratio (SMR) is 78% for the males, 54% for the females, and 68% for both sexes combined. All three SMR values are significantly less than 100% (P less than 0.05). For both sexes combined, the SMR is 86% for cancer, 62% for total cardiovascular diseases, and 73% for all other causes. Only the cardiovascular SMR is significantly lower than 100%. The death rate for the males is approximately the same as that reported among other healthy nonsmoking questionnaire respondents. but the death rate for females is significantly less (P less than 0.01). The only notable relationships between questions asked in 1974 and subsequent mortality are those indicating a higher mortality rate associated with inactivity, heart trouble, and very low and very high levels of vitamin E intake. For this highly selected cohort, the overall "Prevention life-style" appears to be a healthy one, but the cohort experiences no clear reduction in total mortality because of high levels of vitamin intake per se.

Reassessment of the role of dietary fat in cancer etiology.

The role of dietary fat in cancer etiology is briefly discussed in terms of several major types of epidemiological evidence: geographic correlations, migrant studies, low-risk populations, and dietary modification trials. It appears that there is no conclusive evidence that lowering dietary fat intake will result in lowering the cancer death rate. Furthermore, it appears possible to have a relatively low death rate from "diet-related" cancers with an average fat intake. However, in order to fully assess the fat hypothesis, it is important to identify and carefully study a group of Americans with a genuine low-fat diet.

Cancer mortality among Mormons in California during 1968--75.

On the basis of Church records, detailed cancer and total death rates were determined for an average of 360,000 California Mormons during 1968--75, for an average of 700,000 Utah Mormons during 1970 and 1975, and for a subgroup of active Mormon males known as High Priests and Seventies. For cancer as a whole, the standardized mortality ratio was 68% for all California Mormon males, 83% for all California females, and 50% for active Mormon males in California and Utah compared with 1970 U.S. whites. Age-specific and age-adjusted total mortality rates were substantially lower in Mormons than in 1970 U.S. whites, with the greatest differences occurring between 35 and 65 years of age, where the rates for active Mormon males were reduced by more than 60%. Methodologic issues and sources of error were discussed, and the overall quality of the data was good. Some health-related characteristics of Mormons are also summarized.

Cancer mortality among a representative sample of nonsmokers in the United States during 1966--68.

Data are presented on cancer and total mortality among a representative sample of nonsmokers and the total population 35--84 years of age in the United States during 1966--68 that measured the influence of cigarette smoking on mortality rates, independent of other health-related factors. Of all U.S. white males, those who never smoked cigarettes have a total age-adjusted cancer death rate which is 37% less than that of males as a whole and 53% less than that of those who currently smoke cigarettes. Correspondingly, of all U.S. white females, those who never smoked cigarettes have a total age-adjusted cancer death rate which is 15% less than females as a whole and 33% less than that of those who currently smoke cigarettes. The largest cancer rate reduction in the nonsmokers is concentrated in the respiratory system. Nonsmokers have an age-adjusted total death rate which is about 20% less than the population as a whole and about 43% less than current cigarette smokers. These and other results and methodologic issues are discussed.