Peer reviewed: megacities: sweet dreams or environmental nightmares?

Absent external financing mechanisms, megacity problems in developing nations may be insurmountable.

Tobacco, youth, and sports

Cigarette smoking constitutes the single largest threat to the health and longevity of American youth. Each year, almost 400,000 people die prematurely from tobacco-related diseases. Moreover, 90% of adult smokers began using tobacco before their eighteenth birthday, and each day 3,000 children and adolescents begin smoking. Smokeless tobacco use is less prevalent than cigarette smoking but has similar deleterious health effects and is often also glamorized by sports figures. This article examines the relationship between tobacco and sports and offers specific steps that physicians (specifically orthopedic surgeons and sports medicine physicians, who interact with athletes at sporting events and in schools as well as at the clinic) can take to help prevent or minimize tobacco use. Although sports have been used by the tobacco industry to promote tobacco products to young people, the authors suggest new ways to prevent its success.

Prevalence of cigar use in 22 North American communities: 1989 and 1993

OBJECTIVES

This study examined the prevalence rate of and characteristics associated with cigar use.

METHODS

Data were derived from population-based telephone surveys of adults conducted in 22 North American communities in 1989 and 1993 as part of the National Cancer Institute's Community Intervention Trial for Smoking Cessation.

RESULTS

Averaged across the 22 communities, the prevalence rate of regular cigar use increased 133% from 1989 to 1993. Regular cigar use increased in every gender, age, race, income, education, and smoking status category.

CONCLUSION

These results confirm other data indicating that cigar use is increasing.

A Voluntary Smokers' Registry: Characteristics of joiners and non-joiners in the Community Intervention Trial for Smoking Cessation (COMMIT)

OBJECTIVES

This paper examines differences between joiners and nonjoiners of a voluntary smokers' registry.

METHODS

A baseline prevalence survey was used to identify characteristics of smokers who joined or did not join a smokers' registry.

RESULTS

Communities varied significantly in registry enrollment rates. Heavy-smoking joiners expressed more desire to quit, were more likely to live with nonsmokers, and were older than nonjoiners. Light-to-moderate joiners smoked more, were more addicted to cigarettes, and expressed more desire to quit than nonjoiners.

CONCLUSIONS

Few baseline characteristics differentiated joiners from nonjoiners. Nonjoiners were significantly more likely to achieve cessation than joiners.

Effect of proxy-reported smoking status on population estimates of smoking prevalence

The use of proxy respondents in surveys designed to provide population estimates of smoking prevalence offers an inexpensive way to obtain these data. The accuracy of this information is examined in analyzing data from tobacco use surveys of adults conducted in 22 North American communities as part of the National Cancer Institute's Community Intervention Trial for Smoking Cessation. Proxy-reported smoking status was obtained in a cross-sectional telephone survey conducted from August 1993 to January 1994 (n = 99,682). Self-reported smoking status was obtained from an in-depth interview of a sample of the respondents aged 25-64 years enumerated from the telephone survey (n = 31,417). Discrepancy rates were calculated by comparing the proxy-reported and self-reported smoking statuses of a given individual (n = 10,226). In both surveys, respondents were categorized as current smokers (those who currently smoke and have smoked at least 100 cigarettes in their lifetime), recent quitters (< or = 8 years since cessation), long-term quitters (> 8 years since cessation), and never smokers. The overall discrepancy rate between the self-report and the proxy report was 5.4%. Self-respondents who were black, Hispanic, Asian, recent quitters, or aged 25-34 years were more likely to have inconsistent proxy reports. The authors estimate that the screener interview underestimated the true smoking prevalence by 0.1% when they corrected for smoking status discrepancies. These results confirm that proxy-reported smoking status is an accurate and effective means to monitor populationwide smoking prevalence of adults.

Comparison of recent trends in adolescent and adult cigarette smoking behaviour and brand preferences

OBJECTIVE

To compare trends in smoking behaviour and use of cigarette brands by adults and adolescents.

DESIGN

Data analysed in this paper come from tobacco use surveys of adults and teenagers conducted in 18 communities in the United States, as part of the National Cancer Institute's Community Intervention Trial for Smoking Cessation. Data on adult smoking behaviour were obtained from two cross-sectional telephone surveys, one conducted from January to May 1988 (n = 99348), and the second conducted between August 1993 and January 1994 (n = 79890). Data on adolescent smoking behaviour were obtained from two school-based surveys of ninth-grade students (aged 13-16 years), one conducted in autumn 1990 (n = 7097), and the second conducted in autumn 1992 (n = 7277).

OUTCOME MEASURES

Adult cigarette smoking prevalence was estimated as the percentage of adults (18+ years) who were identified either by interview or by proxy as a current smoker. Among adolescents, current smokers were defined as those who reported having smoked on one or more of the 30 days preceding the interview. Cigarette brand use by adults was measured by asking current smokers to report the six digit UPC code on the side of the pack of their current cigarettes. A master list of UPC code numbers was developed so that reported codes could be associated with specific brand names. Among adolescents, cigarette brand use was measured by asking current smokers who reported that they usually buy their own cigarettes: "What brand do you usually buy?"

RESULTS

In ninth-grade students, smoking prevalence rates increased between 1990 and 1992 in 13 of the 18 communities. Among adults, smoking rates declined between 1988 and 1993 in 17 out of 18 communities. Within the same communities, cigarette brand use was found to be much more tightly concentrated in adolescent smokers compared with adults, with teenage smokers more likely to report using the most heavily advertised cigarette brands--Marlboro, Newport, and Camel.

CONCLUSIONS

Smoking prevalence rates have increased among teenagers, but have dropped among adults in the same communities. Among adolescents who smoke, and buy their own cigarettes, the three most heavily advertised brands--Marlboro, Camel, and Newport--have a substantially higher market concentration than among adult smokers.

Predictors of smoking cessation in a cohort of adult smokers followed for five years

OBJECTIVE

To identify variables predictive of smoking cessation in a cohort of cigarette smokers followed for five years.

DESIGN

Data analysed in this paper come from a cohort tracking telephone survey of 13415 cigarette smokers aged 25-64 years from 20 American and two Canadian communities who were interviewed in 1988 and re-interviewed in 1993 as part of the National Cancer Institute's Community Intervention Trial for Smoking Cessation. Predictors of smoking cessation evaluated in this study included measures of past and current smoking behaviour, past quit attempts, stated desire to quit smoking, and demographic characteristics.

OUTCOME MEASURES

Smoking cessation was based on self report. A "quitter" was defined as a cohort member who, at the final annual contact in 1993, reported not smoking any cigarettes for the preceding six months or longer. Any smoker who reported having made a serious quit attempt between 1988 and 1993 was asked to indicate reasons that contributed to their decision to try to stop smoking.

RESULTS

67% of smokers reported making at least one serious attempt to stop smoking between 1988 and 1993 and, of these, 33% were classified as having quit smoking in 1993. The most common reasons given for quitting smoking were concern over health (91%), expense (60%), concern about exposing others to secondhand smoke (56%), and wanting to set a good example for others (55%). Statistically significant predictors of smoking cessation included male gender, older age, higher income, less frequent alcohol intake, lower levels of daily cigarette consumption, longer time to first cigarette in the morning, the use of premium cigarettes, initiation of smoking after age 20, history of past quit attempts, a strong desire to stop smoking, and the absence of other smokers in the household. Predictor variations with the largest relative risks for smoking cessation were those associated with nicotine dependence such as amount smoked daily and time to first cigarette in the morning.

CONCLUSIONS

Despite the fact that most smokers expressed a strong desire to stop smoking in 1988, the majority, especially the most dependent heavy smokers (>25 cigarettes/day), struggled unsuccessfully to achieve this goal.

Cigarette smoking among U.S. adults by state and region: estimates from the current population survey

BACKGROUND

Cigarette smoking is responsible for at least one third of all cancer deaths annually in the United States. Few sources exist in the peer-reviewed literature documenting state and regional differences in smoking behavior, despite the fact that cancer prevention and control efforts are increasingly being implemented below the national level.

PURPOSE

Our goals were to determine smoking prevalence rates among men and women, by region, and for each of the 50 states and the District of Columbia from census survey data collected in 1992 and 1993 and to compare these rates with rates determined in 1985.

METHODS

Every month, the U.S. Bureau of the Census collects labor force statistics on more than 100000 individuals on its Current Population Survey (CPS). For the September 1992, January 1993, and May 1993 CPS, the National Cancer Institute sponsored a 40-item Tobacco Use Supplement. The definition of a current smoker changed slightly between 1985 and 1992-1993. For the 1985 CPS, individuals were considered current smokers if they had smoked 100 cigarettes in their lifetime and were smoking at the time of interview; for the 1992-1993 CPS, current smokers included anyone who had smoked 100 cigarettes and was currently smoking every day or just on some days. We calculated current smoking rates (every day and some days combined) based on more than a quarter million adults (n = 266988) interviewed in 1992-1993.

RESULTS

Substantial geographic variation exists in rates of current cigarette use among adults within the United States. In general, adults in the southern United States have higher rates of smoking and adults in the western states have lower rates of smoking and adults in the rest of the country, although differences in smoking behavior between men and women and among various racial and ethnic populations strongly influence these patterns. Only two states, Kentucky and West Virginia, exhibited adult smoking rates (men and women combined) of 30% or higher in 1992-1993; in contrast, in 1985, such rates were reported from 20 states. The only states in which the prevalence was below 20% in 1992-1993 were Utah (17.1%) and California (19.5%). Rates approaching 20% were reported from New Jersey (20.7%), Massachusetts (21.5%), and Nebraska, New York, and Hawaii (22.0% each) in 1992-1993. Rhode Island experienced the greatest relative decline in smoking prevalence from 1985 to 1992-1993, with a calculated relative change of -30.7% (based on a change in rate from 33.5% to 23.2%), followed by Delaware (-25.9%) the District of Columbia and New Jersey (-23.9% each), Connecticut (-23.2%), California (-22.9%), Alaska (-22.8%), Georgia (-22.6%), Massachusetts (-22.1%), and New York (-22.0%).

CONCLUSIONS

Smoking rates are not uniform in the United States but vary considerably from state to state, even within the same region of the country. The CPS is the only mechanism currently capable of simultaneously monitoring smoking trends nationally, regionally, and on a state-by-state basis.

Interplay between design and analysis for behavioral intervention trials with community as the unit of randomization

This paper outlines an approach for the design and analysis of randomized controlled trials investigating community-based interventions for behavioral change aimed at health promotion. The approach is illustrated using the Community Intervention Trial for Smoking Cessation (COMMIT), conducted from 1988 to 1993, involving 11 pairs of communities in North America, matched on geographic location, size, and sociodemographic factors. The situation discussed is when assignment to intervention is done at the community level; for COMMIT, the very nature of the intervention required this. The number of communities as a key determinant of the statistical power of the trial. The use of matched pairs of communities can achieve a gain in statistical efficiency. Randomization is used to obtain an unbiased assessment of the intervention effect; randomization also provides the basis for statistical analysis. Permutation tests (and corresponding test-based confidence intervals), using community as the unit of analysis, follow directly from the randomization distribution. Within this framework, individual-level covariates can be used for imputation of missing values and for adjusting analyses of intervention effect.

Smoking behavior, workplace policies, and public opinion regarding smoking restrictions in Maryland

The Maryland Occupational Safety and Health (MOSH) advisory board recently proposed a smoking ban in most Maryland workplaces, including bars and restaurants, unless smoking is restricted to a separately ventilated area where nonsmoking workers cannot be required to enter. Results from the 1992-1993 Current Population Survey strongly suggest that there is broad support among Maryland residents for such restrictions and that the MOSH rules would merely extend an already widespread practice in the state. Efforts by the tobacco industry to gain an injunction against the proposed MOSH regulations would not appear to be supported by a clear majority of Maryland residents.

Prevalence of cigarette smoking in the United States: estimates from the 1985 current population survey

In September 1985, the Census Bureau collected health information on 114,342 individuals as part of its Current Population Survey (CPS). A special supplement that included questions on smoking practices was sponsored by the Office on Smoking and Health. The CPS, with its large sample size, provides a unique opportunity to examine region, division, and state estimates of smoking prevalence. The overall prevalence rate for males in the 1985 CPS was estimated at 31.3%, compared with 25.0% for females. For males, smoking rates were highest in the South (34.5%) and lowest in the West (28.0%). For females, smoking rates were highest in the North Central region (26.3%) and lowest in the West (22.7%). Among males, blacks reported higher smoking rates (37.2%) than whites (30.7%) or Hispanics (30.9%). In contrast, white females (25.8%) and black females (26.0%) reported virtually identical smoking rates, while Hispanic females reported a considerably lower rate (16.5%). White-collar workers (both males and females) also reported substantially lower smoking rates than service or blue-collar workers. For both males and females, peak smoking prevalence occurred in the 40-49-year age group (males = 38.1%, females = 30.6%).

Use of smokeless tobacco in the United States: recent estimates from the current population survey

Chewing tobacco, snuff, and total smokeless tobacco use from the 1985 Current Population Survey (CPS) are reported. The CPS is the only survey capable of providing national, regional, and individual state tobacco use estimates for all 50 states and the District of Columbia. The prevalence of smokeless tobacco use varies considerably among and within regions of the country, by division and state. Smokeless tobacco use is highest in the South and lowest in the Northeast. Individual states with the highest smokeless tobacco use among males are West Virginia (23.1%), Mississippi (16.5%), Wyoming (15.8%), Arkansas (14.7%), and Kentucky (13.6%). In all regions of the country, use of smokeless tobacco among women is considerably less than men. Nationally, male use of such products was 5.5%; less than 1% of women use them. Snuff consumption is predominantly a behavior characteristic of white males; less than 1% of black or Hispanic males consume this product. Higher percentages of blue-collar and service workers use it compared with white-collar workers. Snuff and chewing tobacco use among teenage boys in the United States increased dramatically between 1970 and 1985, a time when their use of cigarettes was declining. The significance of individual state level estimates is discussed.

Studies on an antineoplastic fraction from human urine. Characterization of the major protein in this fraction

A fraction has been isolated from human urine which exhibits antiproliferative activity against human tumour cell lines without affecting the growth of several normal diploid cell lines or tumour cells of mouse or hamster origin. The major protein present in this fraction has been characterized and tentatively designated antineoplastic urinary protein (ANUP). An S020,W value of 3.69 S was obtained by sedimentation velocity analysis, and a subunit molecular mass of 16 300 Da was obtained by sedimentation equilibrium and by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Centrifugation data also indicated that the protein self-associates. The amino acid analysis of ANUP was consistent with its low pI (4.2) as determined by chromatofocusing analysis. Furthermore, the amino acid composition exhibited some features similar to collagen, as shown by high levels of proline and glycine, the absence of cysteine, and the presence of low levels of hydroxyproline.

Purification and characterization of B-protein from human serum

B-Protein, present in the serum of individuals with cancer, has been purified to electrophoretic homogeneity. The purification procedure consisted of chromatography on Sephacryl S-200, Affi-Gel Blue, Con A--Sepharose 4B, wheat germ lectin--Sepharose and preparative polyacrylamide gel electrophoresis. The molecular weight of B-Protein is estimated to be 100 000 to 120 000. It is a glycoprotein which appears to be composed of two subunits, each with a molecular weight of approximately 52 000. Analytical polyacrylamide gel electrophoresis and analytical ultracentrifugation data indicate that purified B-Protein is homogeneous. Isoelectric focusing studies also show the purified B-Protein to be homogeneous in composition consisting of a single band of pI = 4.8. Amino acid analysis is consistent with this acidic isoelectric point. Other analyses indicate that B-Protein contains 7% carbohydrate and 7% lipid in the form of triglycerides.

Systems analysis of a host-parasite interaction

Most epidemiological models assume that disease is the inevitable outcome of infection (see Bailey, 1957). Yet as Dubos (1965) has said; ‘Throughout nature, infection without disease is the rule rather than the exception’. There are, in fact, many diseases whose distribution cannot be explained solely by a consideration of the probabilities of host parasite encounters. In these cases, a diseased state is only one possible outcome of an interaction between parasite phenotypes, host phenotypes and the external environment. Haemonchosis is an example of such a disease and has been studied extensively in quantitative terms (see Whitlock & Georgi, 1968).