Data were analyzed with SAS analytic software.8 Means and firequencieswere exam- ined, and an analysis of covariance was used to test the null hypothesis ...
Trends in Cigarette Smoking: The Minnesota Heart Survey, 1980 Through 1992 Donna K. Arnett, PhD, J. Michael Spraflca, PhD, Paul G. McGovern, PhD, David R. Jacobs, Jr, PhD, Eyal Shahar, MD, Maribet McCarty, MPH, and Russell V. Luepker, MD
Introduction Cigarette smoking contributes substan-
tially to death and disability worldwide.' In the United States alone, smoldng contributes to 1 of every 6 deaths overall, including premature deaths from cancer, coronary heart disease, stroke, and chronic obstructive pulmonary disease. Public health efforts directed toward tobacco control have been implemented during the past 3 decades, including educational programs designed to prevent smoking initiation and augment smoking cessation, environmental changes, economic disincentives, and legislative constaints on tobacco sales. As a result; the estimated prevalence of cigarette smoking among adults decreased from 40% in 1965 to 30% in 1987.2 5 The Minnesota Heart Survey previously reported significant declines in the prevalence of cigarette smoking from 1980 through 1982 to 1985 through 1987 among adults 25 to 74 years of age.6 In 1990 through 1992, the project conducted another population survey. This report describes trends in the prevalence of cigarette consumption and cigarette smoking behaviors between 1980-1982 and 1990-1992 in Twin Cities residents 25 to 74 years of age.
Methods The Minnesota Heart Survey is a population-based surveillance of coronary heart disease risk factors in probability samples of residents 25 to 74 years of age in the Minneapolis-St. Paul metropolitan area. Methods have been reported previously.6 The first survey was conducted in 1980-1982; surveys using similar sampling strategies and protocols were repeated in 1985-1987 and 1990-1992. Following household enumeration, one individual 25 to 74 years of age was randomly selected for a 30-minute home interview to determine sociodemographic characteristics, health attitudes and beliefs, and smoking behavior. The exception to this practice was the 1980/81 cycle, during which all ageeligible individuals were sampled. Subjects were then invited to a survey center to complete questionnaires and undergo physiologic measurement.
While information on smoking status was requested in the home interview and the survey center, detailed questions ding cigarete smoking status, brand name, cessation behaviors, and other forms of tobacco use were asked only at the center. Participants who were recent quitters (former smokers who reported quitting within the previous 12 months) were asked a series of standard questions regarding age at initiation, usual brand, and number of cigarettes smoked per day while they were smokers. Current smokers provided information regarding number of cigarettes smoked per day, use of low-tar cigarette brands, and intention to quit during the next year. Participants who reported smoking more than 100 cigarettes in their lifetime were categorized as ever smokers; former smokers were ever smokers who had reportedly quit. Individuals who consumed more than 25 cigarettes per day were defined as heavy smokers. As a means ofvalidating reported consumption, a blood specimen was obtained and analyzed for serum thiocyanate according to the method of Butts et al.7 In all surveys, smokers were significantly less likely to participate in the survey center examination than nonsmokers. Estimates were based on data from the home interview to avoid underestimation of smoking prevalence. Analyses regarding smoking pattems and cessation behaviors were based on the survey center infonnation. Data were analyzed with SAS analytic software.8 Means and firequencies were examined, and an analysis of covariance was used to test the null hypothesis of no differences in age-adjusted sex-specific means between 1980-1982, 1985-1987, and 1990-1992.
Results Cigarette smoking declined significantly between 1980-1982 and 1985-1987 and The authors are with the Division of Epidemiology, School of Public Health, University of Minnesota,
Minneapolis. Requests for reprints should be sent to Donna K. Arnett, PhD, Division of Epidemiology, School of Public Health, University of Minnesota, 1300 S Second St, Suite 300, Minneapolis, MN 55454-1015. This paper was accepted December 3, 1997.
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between 1985-1987 and 1990-1992, prevalences decreasing by 23% and 25% among men and women, respectively (Table 1). The greatest absolute decline occurred in men 25 to 34 yeas ofage (10.1%) and women 35 to 44 years of age (14.0%). Thiocyanate declined significantly in parallel to reductions in smoking prevalence (Table 1). The gratest absolute declines in thiocyanate were also observed for men 24 to 34 years old (20.8 pmol/L) and women 35 to 44 years old (26.2 pmollL). Among current smokers, the overall ageadjusted number of cigarettes consumed per day declined significantly in both men and women between 1980-1982 and 1990-1992 (Table 1).
The prevalences of never, former, and current smoking are shown in Figure 1. The prevalence of never-smoking status increased significantly in men and women between 1980-1982 and 1990-1992 (P < .001), while the prevalence of former smoking declined only slightly in men during the final survey period. Former smoking prevalence increased significantly between 1980-1982 and 19851987 and decreased slightly thereafter (differences were significant in men only). Smoking behavior trends among current smokers are shown in Table 2. Age at initiation was unchanged in men but decreased in women over time, while the rate of switching to low-tar cigarettes declined significantly
in both men and women. Attempts to reduce the number of cigarettes consumed increased between 1980-1982 and 1985-1987 but not thereafter. Quit attempts followed a similar pattem, while attendance at quit programs was low in each survey period. Other forms of tobacco use (e.g., pipe, cigar, chewing tobacco) declined significantly over time in men but were unchanged in women.
Discussion Data from the Minnesota Heart Survey indicate that smoking prevalence and quantity of cigarettes consumed among smokers
TABLE 1 -Age-Adjusted Prevalence of Cigarette Smoking, Serum Thiocyanate, and Number of Cigarettes Smoked per Day, by Age Category, Sex, and Survey Year: Minnesota Heart Survey, 1980-1992
Age group, y
25-34 Prevalence, % Thiocyanate, pmol/L Cigarettes per day, no. 35-44 Prevalence, % Thiocyanate, pmol/L Cigarettes per day, no. 45-54 Prevalence, % Thiocyanate, pmol/L Cigarettes per day, no. 55-64 Prevalence, % Thiocyanate, pmol/L Cigarettes per day, no. 65-74 Prevalence, % Thiocyanate, pmol/L Cigarettes per day, no. Total Prevalence, % Thiocyanate, pmol/L Cigarettes per day, no.
Women
1980-1982 (n = 1855)
Men 1985-1987 (n = 2712)
1990-1992 (n = 2785)
1980-1982 (n = 2196)
1985-1987 (n = 3021)
1990-1992 (n = 3209)
40.0 82.3 23.2
33.4 71.7 21.3
29.9 61.5 18.2
37.5 72.2 20.9
29.5 59.2 16.6
31.2 57.0 14.6
35.4 83.3 27.2
33.0 77.1 23.7
29.3 67.8 20.7
38.9 83.2 23.9
28.3 63.5 20.0
24.9 57.0 16.6
35.7 83.9 25.7
26.9 72.5 25.0
27.2 67.3 23.2
32.3 71.4 20.3
29.3 70.2 20.5
25.7 61.4 19.2
25.4 66.6 26.6
26.2 69.7 27.4
17.6 55.6 21.7
28.0 62.8 19.7
28.7 71.0 18.4
20.7 55.1 16.1
19.4 58.5 19.3
15.4 49.0 21.8
13.8 45.4 18.8
21.0 46.8 16.5
18.3 48.8 15.1
16.3 43.5 14.8
34.2 78.5 24.9
29.6*** 71.2*** 23.4*
26.3** 62.3*** 20.3***
33.9 70.9 21.2
27.8*** 63.0*** 18.4***
25.5* 56.2*** 16.2***
*P < .05; **P < .01; ***P < .001 (significant difference from preceding period).
TABLE 2-Age-Adjusted Estimates of Smoking-Related Behaviors Reported among Cigarette Smokers, by Sex and Survey Year: Minnesota Heart Survey, 1980-1992 Men 1980-1982 1985-1987 1990-1992 1980-1982 (n = 577) (n = 615) (n = 612) (n = 520)
Average age at initiation, y Tried low-tar cigarettes in past 12 months for > 1 month, % Reduced number of cigarettes in past 12 months, % Tried to quit, % Participate in quit program, % Use other form of tobacco, %
17.8 45.7 58.1 43.6 5.0 14.8
17.8
35.4** 74.5*** 60.0*** 5.9 9.6**
17.5 32.1 67.6** 52.7** 6.7 5.1
19.3 47.9 65.1 41.7 4.9 0.5
Women
1985-1987 (n = 613)
1990-1992 (n = 673)
19.3 34.7*** 78.3*** 61.2*** 5.8 0.2
18.4*** 28.5* 74.7 55.1* 4.8 0.0
*P< .05; **P< .01; ***P< .001 (significant difference from preceding period).
August 1998, Vol. 88, No. 8
American Journal of Public Health 1231
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declined substantially from the 1980s to the early 1990s. These declines were supported by a biochemical marker of cigarette consumption, serum thiocyanate. A plateau in "former" smoking was seen between 19851987 and 1990-1992, pointing to the need for public health initiatives for smoking cessation and an emphasis on prevention of smoking initiation.9 The smoking trends in the Minnesota Heart Survey mirror the decline in prevalence in the United States during the 1980s. National prevalence estimates were reported from the National Health Interview Surveys (NHIS) for adults 18 years of age and olderin 1980, 1985, and 1990.5 Data were collected from in-home interviews or by telephone; estimates were adjusted for nonresponse and weighted to provide national estimates. NHIS respondents were classified as curient smokers if they had smoked 100 or more cigarettes and currently smoked. Among men, the prevalene of current smoldng in the Minnesota Heart Survey was lower than that in the NHIS (34.2% vs 37.6% [1980]; 26.3% [1990-1992] vs 28.4% [1990 only]); anong women, the prevalence of curent smoking in the Minnesota samnple was higher (33.90/o vs 29.3%[1980]; 25.5% [1990-1992] vs 23.5% [1990 only]). These dissimilaities may be due to methodological differences in the 2 studies: the Minnesota Heart Survey involved in-person interviews only, while the NHIS included telephone interviews for participants not at home. The reduction in smoking prevalence in the Minnesota Heart Survey resulted from increased smoking cessation and decreased smoking initiation, which differed considerably by sex and age. Sex- and age-specific estimates of changes between 1980-1982 and 19901992 in the prevalences of current smokers, never smokers (i.e., initiation), and quitters (i.e., cessation among ever smokers) are listed in Table 3. Men were more likely never to start smoking than women (10.4% vs 4.8% increase) but less likely to become former smokers (quitters) (4.4% vs 11% increase) over time. Significant cohort effects in initiation and cessation were observed. Young men (those 25 to 34 years of age) evidenced a large reduction in smoking initiation, while older men (those 55 to 64 years of age) reported quitting more often over time. Women 25 to 34 years of age exhibited a significantly smaller increase in the prevalence of never smoking but higher levels of cessation than men. There was little change between 1980 and 1992 in the rate of smoking cessation among men and women 25 to 34 years of age. The effects of age and period (i.e., survey year) were considered
in this study; however,
acknowledge ambiguity about whether these secular trends in smoking prevalence reflect age or birth cohort effects. We inferred
we
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American Journal of Public Health
MEN 100
90
80
70-
*| *
50i
Current
_ormer 40-F 30
*
Never
20-
10-
34.2
29.6
26.3
1980-82
1985-87
1990-92
WOMEN t00 90
70
Current
60-
*Former
50
40
Never
*
30
20 10
33 9
27.8
25.5
1980-82
1985-87
1990-92
0
FIGURE 1-Age-adjusted prevalences of current, former, and never smoking, by survey year, in men and women.
TABLE 3-Changes in Age-Adjusted Prevalences of Current Smoking, Never Smoking, and Former Smoking Among Ever Smokers, by Age and Sex: Minnesota Heart Survey, 1980-1992
Changes in Women Changes in Men FormerNeverCurrentFormerNeverCurrentSmoking Smoking Smoking Smoking Smoking Smoking Age Group, y Prevalence Prevalence Prevalencea Prevalence Prevalence Prevalencea
25-34 35-44 45-54
-10.1
55-64
-7.8 -5.7
65-74 Totala
-6.2 -8.5
-8.0
16-0b0.4 11.8 7.5 -1.8 14.1 10.4
0.4c
7.3 11.3 3.5 4.4
-6.4 -14.1 -6.6 -7.4 -4.7 -8.5
7.7 8.6 6.0 -2.0
3.8 4.8
2.6 16.7 11.3 17.6 7.1 11.0
aAmong ever smokers. bttest for gender difference: P< .01. Ct test for gender difference: P< .0003.
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that changes in smoking prevalence were largely mediated by age and survey year rather than by cohort and survey year, because social influences to smoke are strong in adolescence and young adulthood and become progressively weaker at older ages. In contrast, social influences to quit smoking or not to smoke at all strengthen at older ages. Because these perceived influences have operated in Westem culture for many years, we believe that social pressure is an important factor in an age effect and is largely independent of when a person was bom. It may be that subtle cohort effects exist; for example, the nature of this pressure and its exact association with age may be changing slowly. Contingent on the current and near-term cultural situation, we attribute most ofthe decline in smoking prevalence in the Minnesota Heart Survey to age rather than to cohort or birth year.
Conclusion In summary, favorable trends in smoking prevalence, cessation, and initiation were observed in the Minnesota Heart Survey from 1980 through 1992. However, earlier smoking initiation and a decrease in behaviors related to smoking cessation suggest tiat smoking trends bear watching in the future. D
References 1. Reducing the Health Consequences ofSmoking: 25 Years of Progress: A Report ofthe Surgeon General. Washington, DC: US Dept of Health and Human Services; 1989. DHHS publication CDC 89-841 1. 2. Novotny TE, Fiore MC, Hatziandreu EJ, Giovino GA, Mills SL, Pierce JP. Trends in smoking by age and sex, United States, 1974-1987: the implications for disease impact. Prev Med. 1990; 19:552-561.
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Introduction With Congress actively considering major tobacco control legislation, public health advocates are drawing attention to the tobacco industry's influence on the political process.' Tobacco companies invested nearly $10 million in the 1996 elections,2 and recipients of this bounty strongly support tobacco interests.3 Tobacco's opponents did not sit out the 1996 campaign, however. The eighth largest political action committee in the United States-one that spent more than $4.1 million on the 1996 election4-is that of the American Medical Association (AMA), a group representing more than 200000 physicians. Campaign contributions from the AMA have not preferentially supported anti-tobacco legislators in the past. An analysis ofthe 1990 and 1992 congressional elections demonstated that the AMA's political action committee significantly favored supporters of tobacco export promotion over opponents by about $1700 on average.5 The AMA's leadership responded to these findings by explaining that its political action committee existed to support "the practice concems of physicians (e.g., confidentiality in the patient-doctor relationship,
physicians' autonomy, the scope of practice, and tort reform)."6 The AMA has fought several key battles for tort reform in recent years, leading what its newspaper, American Medical News, called "medicine's intense lobbying effort" to limit noneconomic ("pain and suffering") damages in malpractice suits to $250 000.7 After tort reform legislation first passed the House of Representatives in 1995, an editorial published in American Medical News credited the success to "the long-term commitment of time and financial resources needed to open and maintain access to lawmakers."8 The AMA has simultaneously intensified its anti-tobacco activities. The organizaion has called for politicians not to accept money from the tobacco industry,9 for investors to divest from tobacco stocks,'1 and for Congress to strengthen the control of the Food and Drug Administration (FDA) over tobacco products The author is with the Boston Medical Center and Children's Hospital, Boston, Mass. Requests for reprints should be sent to Joshua Sharfstein, MD, 9 Spring Park Ave, Jamaica Plain, MA 02130. This paper was accepted March 23, 1998.
American Journal of Public Health 1233
