Pack size, reported cigarette smoking rates, and public health.

The relation between packs containing 25 or 20 cigarettes each and self-reports of daily cigarette intake was examined in surveys of smoking habits from the United States and Canada. More Canadian than US smokers report smoking 25 cigarettes per day (19.3 per cent vs 2.1 per cent). As market share of packs of 25 increases across six regions in North America, reports of smoking 25 cigarettes per day increase. Even if smoke exposure remains constant, smoking statistics are likely to be influenced by pack size.     

Cigarette smoking and body weight in the Cancer Prevention Study I.

To investigate the generality of the association of heavy cigarette smoking with increased body weight, the relation of number of cigarettes smoked per day to relative body weight was examined in baseline data for 891,589 participants in a prospective study initiated in 1959. Although the relative weight of cigarette smokers was consistently lower than that of never and exsmokers, men and women smoking two or more packs of cigarettes per day were more likely to be categorized as moderately or severely overweight and less likely to be categorized as underweight than those smoking 10-20 cigarettes per day, despite somewhat greater educational attainment by heavier smokers. These analyses offer support for the temporal generality of the relation between heavier cigarette smoking and greater body weight, and suggest that this phenomenon cannot be explained by historic trends in the socioeconomic stratification of smoking prevalence or smoking dose.     

Changes in the cigarette consumption of smokers in relation to changes in tar/nicotine content of cigarettes smoked.

Over a 13-year period, 59 per cent of 28,561 smokers decreased the tar and nicotine (T/N) level in the cigarettes they smoked without changing the number of cigarettes smoked to any important extent. On the other hand, more than 54 per cent of the "less than one pack a day" smokers as compared to only 25 per cent of the "one pack or more a day" smokers increased the number of cigarettes smoked. Nicotine dependency plays a minor role in determining the smoking habits of those who continue to smoke on a long-term basis.     

The effects of maternal smoking on fetal and infant mortality

Although maternal cigarette smoking has been shown to reduce the birth weight of an infant, previous findings on the relation between smoking and fetal and infant mortality have been inconsistent. This study used the largest data base ever available (360,000 birth, 2,500 fetal death, and 3,800 infant death certificates for Missouri residents during 1979-1983) to assess the impact of smoking on fetal and infant mortality. Multiple logistic regression was used to estimate the joint effects of maternal smoking, age, parity, education, marital status, and race on total mortality (infant plus fetal deaths). Compared with nonsmoking women having their first birth, women who smoked less than one pack of cigarettes per day had a 25% greater risk of mortality, and those who smoked one or more packs per day had a 56% greater risk. Among women having their second or higher birth, smokers experienced 30% greater mortality than nonsmokers, but there was no difference by amount smoked. The prevalence of smoking in this population was 30%. It was estimated that if all pregnant women stopped smoking, the number of fetal and infant deaths would be reduced by approximately 10%. The higher rate of mortality among blacks compared with whites could not be attributed to differences in smoking or the other four maternal characteristics studied. In fact, the black-white difference was greater among low-risk women (e.g., married multiparas aged 20 and over with high education) than among high-risk women (e.g., unmarried teenagers with low education).     

The economic costs of smoking and benefits of quitting for individual smokers

The results of a study that estimated the expected lifetime economic consequences of cigarette smoking for individual smokers are reported herein. The estimates were obtained by combining age- and sex-specific estimates of the incidence-based costs of three smoking-related diseases (lung cancer, coronary heart disease, and emphysema) with estimates of smokers' increased likelihood of developing these illnesses in each remaining year of life relative to nonsmokers. Estimates of the economic consequences of quitting based on these disease cost estimates and on estimates of exsmokers' probability of future disease relative to continuing smokers are also reported. Both the estimates of the economic costs of smoking and the benefits of quitting were calculated separately for men and women between the ages of 35 and 79 who were light, moderate, or heavy cigarette smokers. While the economic costs of smoking varied considerably by sex, age, and amount smoked, they were significant for all groups of smokers. Costs for a 40-year-old man, for example, ranged from $20,000 for a smoker of less than one pack of cigarettes per day to over $56,000 for a smoker of more than two packs of cigarettes per day. The economic benefits of quitting also were found to be sizable for all groups of smokers.     

Cigarette smoking and small irregular opacities.

A survey of chemical workers by chest roentgenograms was designed to determine whether exposure to acrylic dust and/or cigarette smoking was associated with diffuse abnormalities suggestive of pneumoconiosis. The films were examined without knowledge of dust exposure or smoking habits. The International Labour Office (ILO) classification and standard films were used. Workers with exposure to asbestos were excluded. There was no relation between prevalence of abnormalities and exposure to dust. Among 181 workers 28 had s and/or t small irregular opacities with profusion of 0/1 (23), 1/0 (three), or 1/1 (two). These findings were present in 20% of smokers compared with 2.2% of non-smokers. The prevalence increased with increasing age to 31.6% among smokers aged 50-64. Prevalence was 10% among ex-smokers of cigarettes. Among current cigarette smokers, prevalence was 5.3% in those who smoked less than one pack per day, 31.3% in heavier cigarette smokers, and 52.9% in 17 heavy cigarette smokers aged 50-64. Profusions of 0/1 and 1/0 are classified as "suspect" pneumoconiosis according to the ILO guidelines. The data in this study indicate that such abnormalities are directly related to age and smoking habits among workers not exposed to hazardous dust.     

Cigarette smoking and small irregular opacities.

A survey of chemical workers by chest roentgenograms was designed to determine whether exposure to acrylic dust and/or cigarette smoking was associated with diffuse abnormalities suggestive of pneumoconiosis. The films were examined without knowledge of dust exposure or smoking habits. The International Labour Office (ILO) classification and standard films were used. Workers with exposure to asbestos were excluded. There was no relation between prevalence of abnormalities and exposure to dust. Among 181 workers 28 had s and/or t small irregular opacities with profusion of 0/1 (23), 1/0 (three), or 1/1 (two). These findings were present in 20% of smokers compared with 2.2% of non-smokers. The prevalence increased with increasing age to 31.6% among smokers aged 50-64. Prevalence was 10% among ex-smokers of cigarettes. Among current cigarette smokers, prevalence was 5.3% in those who smoked less than one pack per day, 31.3% in heavier cigarette smokers, and 52.9% in 17 heavy cigarette smokers aged 50-64. Profusions of 0/1 and 1/0 are classified as "suspect" pneumoconiosis according to the ILO guidelines. The data in this study indicate that such abnormalities are directly related to age and smoking habits among workers not exposed to hazardous dust.     

Age at starting smoking and number of cigarettes smoked in Catalonia, Spain

BACKGROUND: Few studies have investigated the association between age at starting smoking and the average number of cigarettes smoked per day in adulthood. To provide further evidence on this issue, we analyzed data from the Catalan Health Interview Survey (CHIS). METHODS: The CHIS was conducted in 1994 on a randomly selected sample (N = 15,000) of the population of Catalonia, Spain. A total of 4,897 current or exsmokers (3,276 males and 1,621 females) were included for analysis. Age-standardized proportions of subjects smoking <15, 15-24, and >/=25 cigarettes/day, age-standardized mean number of cigarettes smoked per day, and multivariate odds ratios (OR) of being a heavy smoker (>/=25 cigarettes/day) according to age at starting smoking (<15, 15-17, 18-19, >/=20 years) were computed. RESULTS: Men who started smoking before the age of 15 smoked on average 5.5 cigarettes more than those who started at age 19 or over. Women who started smoking early in life smoked, on average, 6.8 cigarettes/day more than women who started later. The proportion of smokers of <15 cigarettes/day was higher among subjects who started smoking later. Both for males and for females, the OR of being a heavy smoker significantly increased with decreasing age at starting smoking (OR = 2.4 for males and 4.5 for females who started at age <15 versus >/=20 years). The level of education did not modify the relationship in males, whereas the association with age at starting was only apparent for more educated women. CONCLUSIONS: This study confirms that age at starting smoking is inversely and strongly associated to the number of cigarettes smoked per day. Thus, actions aimed at the prevention or delay of smoking onset among adolescents would have an important beneficial effect.     

Age interacts with heaviness of smoking in predicting success in cessation of smoking.

There is conflicting evidence regarding the relation between heaviness of smoking and the likelihood of quitting smoking. We investigated this issue using the data set of the 1986 Adult Use of Tobacco Survey, a telephone survey of the smoking behavior of noninstitutionalized, civilian, US adults aged greater than 16 years. Analyses were based on a subsample of 4,383 individuals who had made a serious attempt to stop smoking 1-10 years before the survey. Among younger smokers, the lighter smokers (less than 25 cigarettes/day) were the most likely to stop, whereas among older smokers, the heavier smokers (greater than or equal to 25 cigarettes/day) were the most likely to stop. These results indicate that age is an important factor in the relation between heaviness of smoking and success in quitting smoking.     

Demographics and cigarette smoking among women

BACKGROUND. A population-based sample of 893 white women ages 25 to 59 years from five San Francisco, California, Bay Area counties were queried about their demographic characteristics, height, reported weight at age 25, cigarette smoking history, and oral contraceptive and sunscreen use. METHODS. Multiple logistic regression techniques were used to analyze the data. Forty-three percent of the women in the sample had never smoked more than 100 cigarettes, while 27% were current and 30% were former smokers. Separated or divorced women were more likely to have ever smoked. RESULTS. Women who were less educated, single, separated, or divorced or had smoked between 10 and 30 cigarettes per day were less likely to quit smoking. Women with less education and a longer history of smoking smoked more cigarettes per day. Women who had never smoked were more likely to use sunscreen and to report their weight as slightly less at age 25 than were smokers.     

Smoking before, during, and after pregnancy.

We report the first national data on smoking before, during, and after pregnancy. Estimates are based on the 1986 Linked Telephone Survey that reinterviewed 1,550 White women 20-44 years of age who were respondents to the 1985 National Health Interview Survey. An estimated 39 percent of White women who had smoked before pregnancy quit smoking while pregnant (27 percent when they found out they were pregnant and 12 percent later during pregnancy). Women with less than 12 years of education were five times as likely to smoke and one-fourth as likely to quit as those with 16 or more years of education. Women who smoked more than one pack of cigarettes per day before pregnancy were one-fifth as likely to quit as those smoking less. Of the women who quit, 70 percent resumed smoking within one year of delivery. Of those who relapsed, 67 percent resumed smoking within three months of delivery and 93 percent within six months. There is little evidence of educational differentials in relapse rates. The fact that relapse remains high suggests that while health of the fetus is a strong influence on women's smoking habits, women may be less aware of the effect of passive smoke on the infant.     

Cigarette smoking and bronchial carcinoma: dose and time relationships among regular smokers and lifelong non-smokers.

In a 20-year prospective study on British doctors, smoking habits were ascertained by questionnaire and lung cancer incidence was monitored. Among cigarette smokers who started smoking at ages 16-25 and who smoked 40 or less per day, the annual lung cancer incidence in the age range 40-79 was:0.273X10(-12). (cigarettes/day+6)2. (age--22.5)4.5. The form of the dependence on dose in this relationship is subject not only to random error but also to serious systematic biases, which are discussed. However, there was certainly some statistically significant (P less than 0.01) upward curvature of the dose-response relationship in the range 0-40 cigarettes/day, which is what might be expected if more that one of the "stages" (in the multistage genesis of bronchial carcinoma) was strongly affected by smoking. If a higher than linear dose-response relationship exists between dose per bronchial cell and age-specific risk per bronchial cell, this may help explain why bronchial carcinomas chiefly arise in the upper bronchi, for dilution effects might then protect the larger areas lower in the bronchial tree.     

The relationship of smoking and ectopic pregnancy.

A case-control study, using data abstracted between 1983 and 1987 from a large perinatal registry, was conducted to explore the relationship between smoking and ectopic pregnancy. Women with ectopic pregnancy (n = 634) seen at University of Illinois Perinatal Network Hospitals were compared to women who were delivered of a single live-born infant (n = 4287). Adjusted for age and race, women who reported smoking during pregnancy had a greater than twofold risk of ectopic pregnancy (Odds Ratio = 2.5, 95% confidence interval = 1.9, 3.2) compared to women who never smoked. The estimated relative risk rose from 1.4 (95% CI = 0.8, 2.5) for a woman smoking fewer than 10 cigarettes a day to 5.0 (95% CI = 2.9, 8.7) at one and a half or more packs of cigarettes per day (p-value for trend less than 0.001). Although further basic and epidemiologic research is necessary, the observed dose-response relation strengthens the argument that smoking may be a causal factor in the development of ectopic pregnancy.     

Cigarette smoking and stages of change among men and women in Kiev,Ukraine

BACKGROUND: Assisting current smokers to progress towards stopping smoking entails identifying their readiness to stop and understanding the factors that may influence their readiness. Relations were established between certain predictor variables (intensity of smoking, age at initiation, duration of smoking, and gender) and stages of readiness to change smoking behaviour in Kiev, Ukraine. METHODS: Analysis was based on a convenient sample of 536 current smokers who completed a stages-of-change questionnaire in a public square in the centre of Kiev's business district, between 22 and 25 July 2000. Frequency distributions, odds ratios, the Kolmogorov-Smirnov test and the Wilcoxon rank-sum test were used to summarize and describe the data. Tests of significance were based on the 0.05 level. RESULTS: The majority of participants (56.1%) were categorized as precontemplative. Less than 20% of the subjects were prepared for action to change smoking behaviour. Later age at smoking initiation was associated with fewer cigarettes smoked per day. Females were more likely then males to seriously consider cutting down the number of cigarettes they smoked. However, males were more likely to have intentionally quit smoking for at least one day within the past year. CONCLUSION: Information on stages of readiness to stop smoking provided by this study may be useful for improving the effectiveness of smoking cessation programmes in Kiev.     

Cigarette smoking and increased risk of mucinous epithelial ovarian cancer

Several studies have reported that cigarette smoking is associated with an increased risk of mucinous ovarian cancer, but other studies have failed to find such a relation. Using data from the Case-Control Surveillance Study, begun in four US cities in 1976, the authors conducted a case-control study (1976-2001) to examine the association between cigarette smoking and the risk of ovarian cancer of different cell types. Among 709 incident cases of epithelial ovarian cancer, 402 were serous, 74 were mucinous, 106 were endometrioid, and 127 were of other cell types. For mucinous ovarian cancer, the odds ratios were 1.5 (95% confidence interval (CI): 0.7, 3.4) among women who smoked less than one pack of cigarettes per day, 1.4 (95% CI: 0.6, 3.5) among women who smoked one pack per day, and 2.9 (95% CI: 1.2, 7.5) among women who smoked more than one pack per day, relative to never smokers. The odds ratios were 2.5 (95% CI: 1.1, 5.4) for ex-smokers and 1.4 (95% CI: 0.7, 2.9) for current smokers. While women with up to 15 pack-years of smoking had an almost 2.5 times' increased risk of mucinous ovarian cancer, such an increased risk was not found among those with more than 15 pack-years of smoking. There was no association between cigarette smoking and epithelial ovarian cancer of other cell types. Despite inconsistencies in the data, these results strengthen the evidence that cigarette smoking may play a role in the development of mucinous ovarian cancer but not ovarian cancer of other cell types.     

Cigarette smoking among medical students in Belgrade related to parental smoking habits

The smoking behaviour of 54.0% of all medical students in Belgrade University is analysed. About one-third are current smokers. Most male students smoke 11-20 cigarettes per day and most female students smoke 1-10 cigarettes daily. The relationship between parents' and students' smoking habit is distinct, especially in female students and when both parents are smokers. The significant association with parental smoking is present only in students who became smokers before the age of 19 and in students who smoke 11 or more cigarettes per day.     

Dependency, social factors, and the smoking cessation process: the doctors helping smokers study

We analyzed data obtained from a representative sample of the smoking patients (n = 1,338) of 66 family physicians to determine predictors of attempts to stop smoking, desire to quit smoking, and successful smoking cessation. Compared to subjects who made no attempt to quit smoking, subjects who tried to quit smoking tended to be younger, had tried to quit smoking in the year prior to the study, waited longer before smoking their first cigarette of the day, had more desire to quit smoking, and had more social support for quitting. Education and cigarettes smoked per day were not independently related to the subject making a quit attempt. Desire to quit smoking was associated with an attempt to quit in the year prior to the study and social support for smoking cessation (support of spouse, second most important social contact, and physician). Desire to quit smoking was not independently related to age, education, or dependency on cigarettes (measured by the number of cigarettes smoked per day and the length of time a subject waited before smoking the first cigarette of the day). Compared to subjects who tried to quit and failed, subjects who succeeded were older, smoked fewer cigarettes per day, and waited longer to smoke their first cigarette of the day. Spouse support, support of the second most important social contact, and advice of a doctor to quit smoking were not independently related to whether or not a cessation attempt would be successful. These data suggest that successful smoking cessation requires two components: social support to make an attempt to quit and the ability to overcome dependency on cigarettes to make the attempt successful.     

Life expectancy among Japanese of different smoking status in Japan: NIPPON DATA80

BACKGROUND: The life expectancy is an important measure for describing health status among population. Several studies from the United States and Europe showed the harm of smoking by describing the life expectancies with different smoking status. No such study is examined in Japan, the country with the world's highest life expectancy irrespective of high smoking rate among men. METHODS: The abridged life table method was applied to calculate the life expectancies of men and women among different smoking status from age 40 until age 85. Age-specific mortality rates stratified by different smoking status were obtained from follow-up data from random sample in Japanese population (NIPPON DATA80). RESULTS: Proportion of current smokers was 62.9% in men and 8.8% in women at the baseline survey in 1980. The life expectancies of 40-year-old never smokers, ex-smokers and current smokers were 42.1, 40.4, and 38.6 years in men and 45.6, 45.9, and 43.4 years in women. The life expectancy of 40-year-old men who smoked less than one pack per day was 39.0 and was longer than that of those who smoked one or two packs (38.8) and more than two packs (38.1). CONCLUSION: Life expectancy decreased gradually as the grade of smoking increased in the Japanese population.     

Cigarette smoking and the risk of breast cancer

The authors examined the relation between cigarette smoking and breast cancer in the Centers for Disease Control Cancer and Steroid Hormone Study, a multicenter, population-based case-control study. The study compared 4,720 women aged 20-54 years with newly diagnosed breast cancer identified through population-based tumor registries with 4,682 women randomly selected from the same geographic areas. Women who reported ever smoking cigarettes had a risk of breast cancer of 1.2 (95 percent confidence interval 1.1-1.3) compared with never smokers. There was no consistent dose-response pattern with any measure of smoking (pack-years of smoking, average number of cigarettes per day, or total years smoked) and little difference in risk between current and former smokers. There was some variation in risk by age, with slightly higher risk estimates for younger women than for older women. Although current smokers had an earlier natural menopause than did never smokers, the authors found no evidence of a protective effect of cigarette smoking on breast cancer risk. These findings suggest that the risk of breast cancer in women who smoke is the same as, or perhaps slightly higher than, women who have never smoked.     

Comparison of smoking behavior change for SI and UC study groups. MRFIT Research Group.

BACKGROUND. The results of MRFIT smoking intervention program are presented for the 4,103 special intervention and 4,091 usual care men who reported smoking cigarettes at the first screening visit. RESULTS. Among the special intervention men, the reported cessation rate increased from 43.1% at 12 months to 48.9% at 72 months. The reported cessation rate among the usual care men increased from 13.5% at 12 months to 28.8% at 72 months. Among smokers who reported cessation at 72 months, 51.3% of special intervention men and 22.7% of usual care men had quit smoking within the first year and remained abstinent thereafter. Average thiocyanate and expired-air carbon monoxide served as objective measures of smoking and were significantly lower among the special intervention men than among the usual care men over the entire follow-up period. The reported cessation rates at 72 months varied according to initial levels of smoking. Smokers reporting 1-19 cigarettes per day at entry were more likely to quit than heavier smokers. For each category of smoking at entry (1-19, 20-39, and 40 or more cigarettes per day) significantly more special intervention than usual care smokers reported cessation. CONCLUSION. These results indicate that the MRFIT smoking intervention program was successful in promoting early cigarette smoking cessation and maintaining cessation over the entire trial for a large percentage of cigarette smokers.