Adolescent smokeless tobacco use: future research needs

Future research needs in the area of adolescent smokeless tobacco use are addressed, based on the studies reported in this volume covering methodologic issues and substantive directions. In addition, we outline some implications for developing preventive interventions to deter smokeless tobacco use among adolescents.     

Epidemiology of smokeless tobacco use: a national study

The prevalence and patterns of smokeless tobacco use and its correlates were assessed in the National Institute on Drug Abuse National Household Survey of residents 12 years of age and older. Overall, 11% of the general population have "ever tried" chewing tobacco, snuff, or other smokeless tobacco. Of these, 5% were former users and 3% used smokeless tobacco almost daily in the past year. Rates of its use differed significantly by sex, age group, race, region, and metropolitan area size. Although females were far less likely to try it, those who did were as likely as males to be daily users. Smokeless tobacco users were also more likely to use alcohol, cigarettes, and marijuana. In general, those who used smokeless tobacco almost daily were more likely to report poor health and hospitalization for illness or injury in the past year, even when other substance use was controlled. Smokeless tobacco users also were more likely to report symptoms of depression. Finally, some substituted smokeless tobacco for cigarettes, but youths (12-17 yr old) were more likely than older tobacco users to use both forms of tobacco regularly.     

Prevalence and predictors of smokeless tobacco use: Iowa's program against smoking

Data from surveys of adolescents were analyzed so that we could determine the prevalence of smokeless tobacco use and identify and compare the concurrent correlates of its use and cigarette smoking. Panel data from seventh through eleventh and eighth through twelfth graders between 1980 and 1984 and cross-sectional data from seventh graders in 1980 and 1985 suggest that boys are more likely to use SLT than are girls and that the boys' use has increased with age and over time. Concurrent correlates of seventh-grade boys' and girls' SLT use and cigarette smoking were identified with discriminant analyses. Predictors of smokeless tobacco use were compared with those of weekly smoking for boys and girls separately. Predictors of use by boys were also compared with those by girls. Trying alcohol and the other form of tobacco were the only predictors that related to the use of either form by boys and girls. Differences among other predictors were noted and their implications for prevention are discussed.     

Initiation and use of smokeless tobacco in relation to smoking

Questionnaire data obtained from 1,631 tenth grade students in 14 school districts in the State of Washington are used in this investigation of the relationship between the onset processes for smokeless tobacco use and smoking. Emphasized is the use of time-to-event data on the ages of occurrence of six events in these onset processes. Concepts and methods for the statistical analysis of time-to-event data are demonstrated. The occurrence of events in the smoking onset process are strongly related to increases in the subsequent onset rate for smokeless tobacco use. Compared with before initial smoking has occurred, the onset rates for weekly smokeless tobacco use after initial smoking has occurred are 2.03 (P less than .001) and 6.72 (P less than .001) times as large for males and females, respectively. Furthermore, both initial and weekly use of cigarettes contributes to the risk of subsequent weekly smokeless tobacco use. Conversely, the steps in the onset process of smokeless tobacco use are strongly related to increases in the subsequent smoking onset rate. Possible implications for intervention in prevention of smokeless tobacco use and for further research are discussed.     

Parent characteristics, perceived health risk, and smokeless tobacco use among white adolescent males

The results of this study indicate that father education, father use of smokeless tobacco, and adolescent risk perception contribute to the use of smokeless tobacco by white males 12 to 14 years of age. However, risk perception does not account for the correlation between parent characteristics and child behavior. Father education and child smokeless tobacco use are inversely related if the father does not use it, and they are directly related if the father does; this finding is consistent with theories of modeling but is contrary to the common observation that the use of some abusive substances is relatively low among adolescents in higher social and economic levels. We concluded that father characteristics should be considered in research and in programs pertaining to the use of smokeless tobacco by white adolescent males.     

A comparison of the use of smokeless tobacco in rural and urban teenagers

This paper compared the use of smokeless tobacco and its effects in rural and urban teenagers. A random sample of 445 subjects from rural Colorado were examined: 82.9 percent of the total sample were Caucasian, and 94.6 percent of those who used smokeless tobacco were Caucasian. This percentage supports the findings of an earlier urban study that the habit is predominantly one of male Caucasians. The average age of the users was 16.7 years, slightly older than in the urban study. Of the rural users, 62.5 percent had lesions of the oral tissues, compared with 48.7 percent lesional incidence in urban users. In both studies, those subjects with lesions had longer daily contact with smokeless tobacco, as well as a longer history of use than those without lesions. These are numerical averages that reflect great individual variations in susceptibility. The average duration of use for rural and urban users with lesions was almost the same; the development of lesions appears to be related to the length of daily exposure, which, on the average, was greater among rural users than urban users. Additionally, more than twice as many degree 3 lesions were found among users in the rural study. The habituating effects of nicotine and the influence of this substance on the future tobacco-usage patterns of youngsters who presently use smokeless tobacco are areas of concern. It is hoped that additional research will further delineate the scope of this current health problem.     

A longitudinal study of smokeless tobacco use and mortality in the United States

Few studies in the United States have examined longitudinally the mortality risks associated with use of smokeless tobacco (SLT). The sample of our study was composed of participants from the National Longitudinal Mortality Study who completed a single Tobacco Use Supplement to the Current Population Survey between the years 1985 and 2011. Using survival methods, SLT use at the baseline survey was examined as a predictor of all‐cause mortality and cause‐specific mortalities in models that excluded individuals who had ever smoked cigarettes, cigars or used pipes (final n = 349,282). The participants had median and maximum follow‐up times of 8.8 and 26.3 years, respectively. Regression analyses indicated that compared to the never tobacco users, the current SLT users did not have elevated mortality risks from all cancers combined, the digestive system cancers and cerebrovascular disease. However, current SLT users had a higher mortality risk for coronary heart disease (CHD) [hazard ratio (HR) (95% CI) = 1.24 (1.05, 1.46)] relative to never tobacco users. In a separate model, the elevated risk for CHD mortality corresponded to the use of moist snuff [HR (95% CI) = 1.30 (1.03, 1.63)]. The associations with CHD mortality could be attributed to long‐term nicotine exposure, other SLT constituents (e.g., metals) or the confounding effects of CHD risk factors not accounted for in our study. The study's findings contribute to the ongoing dialogue on tobacco harm reduction and the US FDA's evaluation of Modified Risk Tobacco Product applications submitted by American SLT manufacturers.     

Bladder cancer risk and pipes, cigars, and smokeless tobacco

Interview data from 2982 patients with bladder cancer and 5782 controls selected from the general population were used to assess the effects of non-cigarette tobacco use on bladder cancer risk. Compared to men who had never smoked, those who had smoked pipes but not cigars or cigarettes had a relative risk estimated at 1.23 (95% confidence interval [CI] = 0.75-2.00). Those who smoked cigars but not pipes or cigarettes were estimated to have a relative risk of 1.33 (95% CI = 0.92-1.94). Little evidence of dose response was observed. The excess relative risk to pipe smokers was limited to those who inhaled deeply.     

Advertising and promotion of smokeless tobacco products

This paper is focused on the approaches used to advertise and promote smokeless tobacco products during the early to mid-1980s. These included traditional motifs that featured rugged-looking masculine models in sporting and outdoor settings as well as an expanded white-collar appeal. Smokeless tobacco was not affected by the ban on broadcast advertising of cigarettes that went into effect in 1971, and, until 1986, both print and broadcast media were used to advertise it. Promotional activities ranged from sponsorship of sporting events to offers for clothing bearing smokeless tobacco product logos. Despite the claims of manufacturers that advertising and promotional efforts were not targeted to youth, smokeless tobacco companies sponsored tobacco-spitting contests with teenage participants, a college marketing program, and college scholarships. In efforts that appeared designed to bolster their public image in the face of growing concern over the consequences of smokeless tobacco use by young people, companies like U.S. Tobacco Company contributed to major social programs, including, ironically, alcohol- and drug-abuse prevention programs. Spurred by public health groups, federal legislation was passed in 1986 that banned television and radio advertising of smokeless tobacco products and required manufacturers to include warning labels on their products on the potential health hazards of smokeless tobacco use.     

Native youth and smokeless tobacco: prevalence rates, gender differences, and descriptive characteristics

This is a report on smokeless tobacco use among Native American youth from Indian reservations in Washington State. Study findings indicate that snuff and chewing tobacco are used frequently, heavily, and at an early age by Native Americans. Nearly one-half of our subjects had used smokeless tobacco on 11 to 20 or more occasions; close to one-third of all the females had used smokeless tobacco on more than 20 occasions. Weekly users in this study were young. Of those Native subjects who used snuff or chewing tobacco weekly, 72% were under 12 years of age. Among youth who reported weekly smokeless tobacco use, about 74% of all females and 90% of all males had first used snuff or chewing tobacco before they were 10 years old. Study results have implications for efforts toward detection, treatment, and prevention of snuff and chewing tobacco use among Native American adolescents.     

Carcinogenic components of smokeless tobacco and tobacco-free cigarettes

The investigation deals with an assessment of carcinogenicity and mutagenicity of samples of smokeless tobacco now on the Russian market as well as ash from alternative cigarettes made of aromatic herbs. Our data showed that the levels of polycyclic aromatic hydrocarbons, volatile and tobacco-specific N-nitrosoamines complied with the standards in the producer-countries. Smokeless tobacco extracts failed to show (Ames) any mutagenic effects such as the "read-out frame shift" or "base-pair replacement" patterns. No tobacco-specific N-nitrosoamines were identified in herbal cigarettes. However, polycyclic aromatic hydrocarbons and volatile N-nitrosoamines content appeared to be identical to that of tobacco. Herbal cigarette smoke extracts mutagenicity induced by side-effects of carcinogenic substances was of similar magnitude as well.     

A systematic review of cancer risk among users of smokeless tobacco (Swedish snus) exclusively,compared with no use of tobacco

The main objective of this systematic review was to assess cancer risk, and mortality after cancer diagnosis, for exclusive users of Swedish snus, compared with non-users of tobacco. We followed international standards for systematic reviews and graded our confidence in the risk estimates using the GRADE approach. Our search gave 2450 articles, of which 67 were assessed in full text against our inclusion criteria. Of these, 14 cohort-studies and one case-control study were included in the review. The studies investigated risk of cancer in the oral cavity or oropharynx (3 studies), esophagus (1 study), stomach (1 study), pancreas (2 studies), colorectum (2 studies), anus (1 study) and lung (1 study), as well as malignant lymphoma (1 study), leukemia and multiple myeloma (1 study), melanoma (1 study), any cancer (1 study) and mortality after cancer diagnosis (4 studies). Cancer risk could only be evaluated in men as there was a general lack of data for women. All included studies were evaluated to have a moderate risk of bias, mostly related to validity of exposure information. An increased risk of cancer of the esophagus, pancreas, stomach and rectum as well as an association between use of snus and increased mortality after a cancer diagnosis was reported. Our confidence in the various risk estimates varied from moderate through low to very low.     

Effectiveness of video instruction in educating teenagers about the health risks of smokeless tobacco use

Smokeless tobacco use, especially among adolescents, appears to have gained increased recent popularity. A resurgence in the use of this product was identified in the mid-1970s. Surveys in the United States have documented that between 8% and 30% of all high school males are regular users of smokeless tobacco products. Investigators have identified specific clinical lesions associated with smokeless tobacco use that appear most frequently as wrinkled mucosal surfaces with delicate white stria. Such lesions have been termed smokeless tobacco keratoses. Gingival inflammation and periodontal inflammation have also been associated with the use of this product. The purpose of the current investigation was to determine the effectiveness of a specific intervention aid, video instruction, for providing teenagers with information concerning the health risk of smokeless tobacco use. The video provided new information to students and appeared to be an effective tool for student health education. It is, however, unclear at this point how well the information will be retained or whether or not viewing the videotape will encourage the student to reconsider the habit and decrease the likelihood that he or she will begin or continue it. These aspects and the long-term impact of the video instruction need to be addressed by a longitudinally designed study and future research on smokeless tobacco use among teenagers.     

Use of smokeless tobacco among male adolescents: concurrent and prospective relationships

The concurrent and prospective correlates of the use of smokeless tobacco among 846 adolescent males were examined. There were 6- and 12-month follow-ups to the initial questionnaire. Substantial levels of tobacco, alcohol, and marijuana use were reported, with 21% reporting use of more than one drug in the last week. Daily smokeless tobacco users were more likely to initiate use of cigarettes, marijuana, and alcohol than were other males. In addition, the "having used" smokeless tobacco variable was related to increased use of cigarettes, marijuana, and alcohol at follow-up. Discriminant analysis of concurrent data identified peer use of smokeless tobacco and experience with cigarette smoking as the primary discriminating factors between males who had tried it and those who had not. Peer use of smokeless tobacco also discriminated between daily users and those who had tried it but had not gone on to become daily users. Thus peer influence seems to be an important factor not just in trial of smokeless tobacco but also in the development of a daily use pattern. Beginning use of smokeless tobacco was related to offers to use alcohol, cigarettes, and marijuana; peer use was the best predictor of continued daily use.     

Bimodal initiation of smokeless tobacco usage: implications for cancer education

One hundred fifty (150) randomly chosen adult male subjects (average age 37) drawn from a university general dental clinic were classified by self-report into three equal categories of fifty smokeless tobacco users, fifty cigarette smokers (non-smokeless tobacco users), and fifty non-tobacco users. According to questionnaire results, a bimodal curve was exhibited among smokeless tobacco users with the two peaks of initiation at ages 12 and 18 compared to a unimodal age of initiation for cigarette smokers at age 16. Two different cohorts of smokeless tobacco users based on age of initiation were observed with differences reported in level of education, urban versus rural origin, average length of time in using smokeless tobacco, and the type of smokeless tobacco product used. Young initiators appeared to be primarily from rural communities having a strong parental or familial influence when initiating smokeless tobacco usage, whereas older initiators appeared to be primarily from more urbanized regions with peer influences as the most significant for initiating smokeless tobacco usage. Other characteristics associated with one or the other cohort were also reported, pointing to different educational measures that may be necessary for prevention and intervention, based on the age of initiating smokeless tobacco usage, as well as place of residence.