Cigarette smoking and adult leukemia. A meta-analysis

BACKGROUND

Increasing evidence suggests that certain forms of adult leukemia may be related to cigarette smoking.

METHODS

To evaluate the association between cigarette smoking and adult leukemia, we conducted a meta-analysis of available studies. Data were identified through an English-language MEDLINE search for the period 1970 through 1992 and through our knowledge of ongoing and unpublished studies. Among the studies identified, the meta-analysis included seven prospective studies and eight case-control studies. The US Surgeon General's criteria were used to assess the evidence for causality.

RESULTS

A positive association between smoking and certain histologic types of leukemia was found in both prospective and case-control studies. The summary smoking-related risk derived from prospective studies (relative risk, 1.3; 95% confidence interval, 1.3 to 1.4) was greater than that based on case-control data (relative risk, 1.1; 95% confidence interval, 1.0 to 1.2). Prospective data suggested an elevated risk of myeloid leukemia associated with cigarette smoking (relative risk, 1.4; 95% confidence interval, 1.2 to 1.6). Pooled case-control data showed increased smoking-associated risk for acute nonlymphocytic leukemia (relative risk, 1.3; 95% confidence interval, 1.1 to 1.5). Risk of leukemia increased according to the number of cigarettes smoked per day. Population-attributable risk calculations suggested that approximately 14% of all US leukemia cases (including 17% of myeloid and 14% of acute nonlymphocytic leukemias) may be due to cigarette smoking.

CONCLUSIONS

The consistency, temporality, and biologic plausibility of this relationship augment our findings, which support a causal relationship between cigarette smoking and certain forms of adult leukemia. Further studies are needed to examine risk among women, dose-response effects, and variation in risk by histologic type.

Restricting minors' access to tobacco: a review of state legislation, 1991

Currently, 46 states and the District of Columbia prohibit the sale of tobacco products to minors, and the minimum age requirement differs by state. In general, these laws are poorly enforced and inadequately prevent youth from obtaining tobacco. According to a four-part classification scheme used in this article, no states have comprehensive laws banning access to tobacco, four states have moderate laws, 37 states and the District of Columbia have basic laws, five states have nominal laws, and the remaining four states have no regulations. We recommend 11 important elements for laws that would adequately restrict minors' access to tobacco products.

Exposure to environmental tobacco smoke in naturalistic settings

BACKGROUND

Exposure to environmental tobacco smoke (ETS) has been identified as a risk factor for chronic disease among nonsmokers. Results of epidemiological surveys suggest that the majority of nonsmokers have regular ETS exposure. However, little is known about the topography of exposure.

METHODS

An exposure diary was used by 186 nonsmokers to self-monitor ETS exposure over a 7-day period. Subjects also completed a questionnaire that assessed their patterns of ETS exposure.

RESULTS

The primary source of ETS exposure was the workplace, except when there was a smoker in the household, in which case the household was the primary source. The presence of a smoker in the household resulted in higher levels of exposure both at work and in other locations when compared with subjects without household exposure. Subjects' assessments of exposure on the questionnaire were consistently lower than their self-monitored levels. This finding suggests that general exposure ratings underestimate exposure.

CONCLUSIONS

This study provides a new understanding of the patterns of ETS exposure and may help guide the development of policies and interventions designed to reduce ETS exposure.

Quantifying the disease impact of cigarette smoking with SAMMEC II software

Smoking-Attributable Mortality, Morbidity, and Economic Costs Software, Release II (SAMMEC II) has been developed for the Office on Smoking and Health, Public Health Service, to permit rapid calculation of deaths, years of potential life lost, direct health-care costs, indirect mortality costs, and disability costs associated with cigarette smoking. For the mortality-related measures, age-specific and age-adjusted rates are also calculated. The pivotal epidemiologic measure in these calculations is the smoking-attributable fraction, and attributal risk measure. A multiple-measure approach (attributable mortality and economic costs) to quantifying a health problem is termed "disease impact estimation." Previously, national and State-specific estimates of smoking-attributable mortality and economic costs were calculated using SAMMEC software, the predecessor of SAMMEC II. SAMMEC II is completely menu-driven and operates within the Lotus 1-2-3 software as a set of linked spreadsheets. SAMMEC II adapts national epidemiologic methods for use by State and local health departments. Increased exposure of public health professionals to disease impact estimation techniques, as demonstrated by SAMMEC II, will lead to improvements in both methodology and the quality of smoking-related health data. The primary purpose of SAMMEC II, however, is to provide State or locality-specific data on the health consequences of smoking to policymakers and public health professionals in these jurisdictions.

Quitting smoking in the United States in 1986

In an analysis of recent behavior with regard to quitting smoking, detailed histories were obtained on a representative sample of 5,623 Americans who had smoked in the year preceding the 1986 Adult Use of Tobacco Survey. An estimated 55.8 million Americans smoked regularly for some period during the year prior to the survey. Approximately one third (34.8%) quit for at least a day during the year prior to the survey, 28.3% quit for at least 7 days during the year prior to the survey, and 16.2% were still not smoking at the time of the survey. Of those who quit for a day, 54% had relapsed by the time of the survey. Demographic characteristics, such as age, sex, race, marital status, and education, were evaluated as predictors of making a major attempt to quit for 7 days or more. Among those who had made a major attempt, a similar analysis was done predicting success in maintaining cessation for 3 months or more. Ordinal logistic regression analyses showed that younger age and higher education predicted a major attempt to quit. There was only one group who differed markedly from all others: those who were younger and were more highly educated. Older age and being white predicted those who abstained for 3 months or longer.

Trends in smoking by age and sex, United States, 1974-1987: the implications for disease impact

Using data from the 1974-1987 National Health Interview Surveys, we report trends in current smoking prevalence and quit ratios (the proportion of those who have ever smoked who no longer smoke) for men and women in the age groups 20-24, 25-44, 45-64, and 65 years and older. Current smoking prevalence decreased linearly for men in all age subgroups except 65 and older and for women ages 25-44 and 45-64 years only. The quit ratios increased linearly within each age/sex subgroup except for men and women ages 20-24 years. Overall, there were about 1.4 million fewer male smokers and over 1 million more female smokers in 1987 than there were in 1974. Between 1974 and 1987, the population ages 25-44 years increased by approximately 47%, and the population 65 years and older increased by approximately 34%. As a result, between 1974 and 1987, the actual number of smokers increased among men ages 25-44 years (8% increase), women ages 25-44 years (15% increase), and women ages 65 years and older (50% increase). These data suggest that even with favorable recent changes in the overall smoking prevalence of the U.S. population, the disease impact of smoking will increase for decades, especially among women. This scenario will be mitigated if increased attention is given to cessation among women in general and to the post-World War II generation of both male and female smokers.

Prevalence of Giardia lamblia and risk factors for infection among children attending day-care facilities in Denver

A sample of children in the toddler age group was surveyed in Denver, CO, to determine the prevalence of Giardia lamblia and to identify risk factors for the intestinal disease. The sample consisted of 236 children attending day-care centers (DCC) and 79 who were not attending. Thirty-eight children (16 percent) attending DCCs and 7 (9 percent) who had not were positive for G. lamblia in stool samples. Risk factors for those attending DCC facilities included increasing duration of attendance, time per week attending DCCs, low family income, and large family size. The only risk factor for those not attending DCC facilities was travel to Colorado mountains. Multivariate analysis showed that risk factors for all children in the sample included travel to Colorado mountains, large family size, and attending DCC facilities. Infection was not associated with symptoms.

State-specific progress toward the 1990 objective for the nation for cigarette smoking prevalence

We predicted the smoking prevalences for 1990 for each state in the US, assuming that the decline in each state from 1985-1990 would be the same as the decline in the US from 1965-1985. In 1985, only three states had smoking prevalences less than 25 percent. Based upon the observed decline in smoking in the US from 1965-1985 of 0.5 percent per year, we predict that only seven states will have smoking prevalences less than 25 percent by 1990. States need to consider current smoking prevalence and achievable rates of decline when setting objectives for 1990 and beyond.

The epidemiology of cigarette smoking and its impact on chronic obstructive pulmonary disease

Since the first Surgeon General's report on smoking and health was released in 1964, the United States has achieved substantial progress in curtailing smoking. Per capita cigarette sales for persons 18 yr of age or older have declined each year since 1973. Total cigarette sales have fallen an average of 1.8% each year since 1982, despite the increasing size of the population. National population-based surveys show that the prevalence of smoking has fallen steadily among adults during the past quarter century. Unfortunately, a parallel decrease in mortality from chronic obstructive pulmonary disease (COPD), one of the most important smoking-related diseases, has not occurred. To estimate the current impact of smoking on mortality from COPD, we used a modified formula for population attributable risk to calculate the mortality and years of potential life lost due to COPD caused by smoking. In 1984, an estimated 51,013 deaths occurred from COPD caused by smoking: 35,638 among men (85% of total COPD mortality) and 15,376 among women (69% of total COPD mortality) (sum does not equal total due to rounding). These deaths resulted in a total loss of 501,290 yr of life before the average life expectancy. We conclude that cigarette smoking continues to cause a heavy burden of premature death from COPD in the United States. This burden may increase in the coming years despite decreasing smoking rates because the residual risk of COPD mortality among former smokers persists for many years.

The reliability of self-reported cigarette consumption in the United States

To investigate the possibility that self-reported smoking is not a valid measure for assessing trends in smoking prevalence, we compared total self-reported cigarette consumption with the adjusted consumption data from cigarette excise taxes as reported by the US Department of Agriculture (USDA) for the period 1974 through 1985. Self-reported consumption was calculated by using data from the National Health Interview Surveys (NHIS) for adults and from the National Household Surveys on Drug Abuse for adolescents. For this period, the average ratio of self-reported cigarette consumption to the USDA estimate of consumption was 0.72 (range = 0.69 to 0.78). There was no statistical difference in this consumption ratio from year to year, indicating no apparent increase in the underreporting of cigarette smoking in these surveys. We conclude that cross-sectional surveys of self-reported smoking status remain a reliable surveillance tool for monitoring changes in population smoking behavior.

Trends in cigarette smoking in the United States. The changing influence of gender and race

Trends in the prevalence, initiation, and cessation of cigarette smoking are reported for the US population using weighted and age-standardized data from seven National Health Interview Surveys (1974 to 1985). The decline in prevalence was linear, with the prevalence for men decreasing at 0.91 percentage points per year to 33.5% in 1985 and the prevalence for women decreasing at 0.33 percentage points per year to 27.6% in 1985. For whites the rate of decline (percentage points per year) was 0.57, to 29.4% in 1985, and for blacks the decline was 0.67, to 35.6% in 1985. Smoking cessation increased among all gender-race groups from 1974 to 1985, with the yearly rate of increase (in percentage points per year) about equivalent for blacks (0.75) and whites (0.77), while it was higher in women (0.90) than in men (0.67). Smoking initiation decreased among young men (-1.03), while it remained about the same in young women (+0.11). Initiation decreased at a more rapid rate in blacks (-1.02) than in whites (-0.35). We conclude that smoking prevalence is decreasing across all race-gender groups, although at a slower rate for women than men, and that differences in initiation, more than cessation, are primarily responsible for the converging of smoking prevalence rates among men and women.

Trends in cigarette smoking in the United States. Projections to the year 2000

Data from National Health Interview Surveys from 1974 through 1985 are used to project cigarette smoking prevalence to the year 2000. Smoking prevalence in the United States has declined at a linear rate since 1974. If this trend continues, in the year 2000, 22% of the adult population (40 million Americans) will be smokers. By the year 2000, the major inequalities in prevalence will occur among educational categories. At least 30% of those who have not proceeded beyond a high school education will be smokers, whereas less than 10% of college graduates will smoke. Among the other sociodemographic subgroups, smoking prevalence is expected to decrease by the year 2000 to 20% among men, to 23% among women, to 25% among blacks, and to 21% among whites. Between 1974 and 1985, approximately 1.3 million persons per year became former smokers, indicating considerable success in public health efforts to encourage people to stop smoking. However, in the early 1980s, approximately 1 million new young persons per year were recruited to the ranks of regular smokers. This is equivalent to about 3000 new smokers each day. Public health efforts need to focus more on preventing young people from starting to smoke, and such prevention efforts should particularly target less educated socioeconomic groups.

Trends in cigarette smoking in the United States. Educational differences are increasing

National trends in smoking prevalence by educational category from 1974 through 1985 show that education has replaced gender as the major sociodemographic predictor of smoking status. Smoking prevalence has declined across all educational groups but the decline has occurred five times faster among the higher educated compared with the less educated. From 1974 to 1985, smoking prevalence among persons with less than a high school diploma declined to 34.2% (0.19 percentage points per year) whereas prevalence for persons with four years or more of college education declined to 18.4% (0.91 percentage points per year). Smoking cessation activity increased across all educational groups, but the rate of increase among the higher educated was twice that of lower-educated groups. Initiation of smoking among more-educated men decreased rapidly to 15% in 1985 but leveled off by 1987. Until 1985, less-educated young females were the only group in which smoking initiation was increasing. However, in 1987 a sudden and large decline in initiation among less-educated females occurred. The apparent recent changes in initiation patterns by educational level suggest that the converging of smoking prevalence between the genders may not continue. The large and widening educational gap in smoking suggests that health promotion priorities need to be reassessed.

Smokeless tobacco use in the United States: the adult use of tobacco surveys

Prevalence of smokeless tobacco use is reported for adults aged 21 years and older in the Adult Use of Tobacco Surveys, 1964-1986. Data from the 1986 survey on prevalence, beliefs, ages of initiation, and demographic correlates of use by males aged 17 years and older are also reported. The prevalence of smokeless tobacco use declined slightly among persons aged 21 and older between 1966 and 1986. However, 5.2% of the males aged 17 and older used smokeless tobacco in 1986, and prevalence was highest among those 17 to 19 years old (8.2%). The median age of initiation for both products was 19 years. Smokeless tobacco use was most common among white men who were 1) living in the southeastern United States, 2) unemployed, and 3) in blue-collar or service/labor employment. Most users (77.4%) and nonusers (83.4%) believe that smokeless tobacco is a health hazard. Many current users (39.1%) had attempted to quit. Some current (6.4%) and former smokers (7.0%) have used smokeless tobacco as an aid to smoking cessation. National survey data such as these permit the identification of high-risk groups, so that interventions against smokeless tobacco use may be specifically targeted.

Smoking by blacks and whites: socioeconomic and demographic differences

Using data from the 1985 National Health Interview Survey for persons aged 25-64 years, we controlled simultaneously for socioeconomic status (SES), demographic factors, and race in multivariate logistic regression analyses. We found that the odds of ever smoking are not higher for Blacks compared with Whites, when the other variables are controlled. By contrast, the odds of heavy smoking for Blacks are far less than for Whites, while Blacks are significantly less likely than Whites to quit smoking regardless of SES or demographic factors. Smoking cessation and prevention programs must be planned with these behavioral, SES, and demographic differences in mind.

New ceramics-related industry implicated in elevated blood lead levels in children

Elevated lead levels have been implicated as a cause of a variety of health problems in children. Blood lead, erythrocyte protoporphyrin, and hemoglobin levels were measured for family members of workers exposed to lead borosilicate dust in a capacitor and resistor plant in Colorado. Previous studies in other lead-related industries have shown an increased risk of lead poisoning among workers' children through exposure to dust brought home on work clothes. Eighty-nine family members of 41 exposed workers were tested along with 62 family members of 30 unexposed comparison households. The mean blood lead level in the family members of exposed workers was significantly elevated compared with that of the unexposed group (10.2 vs. 6.2 micrograms/dl, p = .0001).