Incidence of Initiation of Cigarette Smoking -- United States, 1965-1996

Tobacco use is the single leading preventable cause of death in the United States, and the risk for smoking-attributable disease increases the earlier in life smoking begins (1). Trends in the initiation of cigarette smoking are important indicators for directing and evaluating prevention activities (2). CDC and the Substance Abuse and Mental Health Services Administration (SAMHSA) analyzed self-reported data from the National Household Survey on Drug Abuse (NHSDA) for 1994-1997 to study the incidence of initiation of first cigarette smoking and of first daily smoking in the United States during 1965-1996 among persons aged less than or equal to 66 years and to estimate the number of new smokers aged less than 18 years. The findings from the analysis indicated that, during 1988-1996 among persons aged 12-17 years, the incidence of initiation of first use increased by 30% and of first daily use increased by 50%, and 1,226,000 persons aged less than 18 years became daily smokers in 1996.

The NHSDA samples households, noninstitutional group quarters (e.g., shelters, rooming houses, and dormitories), and civilians living on military bases (3). The surveys for 1994-1997 were administered to a multistage area probability sample (n=78,330) of the U.S. population aged greater than or equal to 12 years. The overall response rates for specific years ranged from 73% to 76%. Data were weighted to provide national estimates, and confidence intervals (CIs) were calculated using SUDAAN{Registered} * (4).

Respondents completed the questionnaire that included questions about cigarette use. To estimate age of first use, respondents were asked, "How old were you the first time you smoked a cigarette, even one or two puffs?" To estimate age of first daily use, respondents were asked, "How old were you when you first started smoking cigarettes every day?" The year of initiation of first use and of first daily use were calculated by subtracting each respondent's date of birth from the interview date and then adding the age of first use or first daily use. Estimates of the number of new smokers for a given year during 1965-1995 (for first use) and 1965-1996 (for first daily use) were calculated by combining data on all respondents and applying sample weights; age-specific estimates for any given year used only data for persons in the respective age ranges during the year (2). Because the calculation of initiation of first use for 1996 would have excluded data on persons aged less than 11 years, estimates of the incidence of first use were not made for 1996. Age-specific (i.e., 5-11 years, 12-17 years, 18-25 years, and 26-34 years) incidence of initiation estimates for a given year were calculated using weighted estimates of the number of persons who were in the relevant age group and who first smoked or first smoked daily during that year divided by the number of persons who were in the relevant age group and who were exposed to risk for first use during the year (weighted by their estimated exposure time measured in years) (2). Incidences are expressed as per 1000 person-years (PY) of exposure. **

Among persons aged 12-17 years, the incidence of first cigarette use decreased from 1974 (132.2) to 1987 (98.6) and increased from 1988 (107.0) to 1995 (139.1) (Table_1). For persons aged 18-25 years, first use decreased from the late 1960s through the late 1980s and increased during the 1990s. For persons aged 5-11 years and 26-34 years, first use was less than 23 throughout the study period.

Among persons aged 12-17 years, the incidence of first daily cigarette use fluctuated from 1966 (42.6) to 1983 (43.8) and gradually increased from 1988 (51.2) to 1996 (77.0) (Table_1). For persons aged 18-25 years, first daily use generally decreased from the 1960s through the early 1990s and then stabilized. First daily use among persons aged 12-17 years was equivalent to that of persons aged 18-25 years during the late 1980s. Among persons aged 26-34 years, first daily use decreased from 1974 (23.7) to 1996 (7.5). During 1965-1988, first daily use was less than 4.3 for persons aged 5-11 years.

The number of new smokers in the United States increased from the 1980s to 1995 and 1996. The number of persons aged less than 18 years who first smoked a cigarette was 1,929,000 (95% CI=plus or minus 153,000) in 1988, 2,175,000 (95% CI=plus or minus 180,000) in 1993, 2,392,000 (95% CI=plus or minus 231,000) in 1994, and 2,441,000 (95% CI=plus or minus 298,000) in 1995. The number of persons aged less than 18 years who first smoked daily was 708,000 (95% CI=plus or minus 84,000) in 1988, 897,000 (95% CI=plus or minus 100,000) in 1993, 1,056,000 (95% CI=plus or minus 112,000) in 1994, 1,174,000 (95% CI=plus or minus 163,000) in 1995, and 1,226,000 (95% CI=plus or minus 196,000) in 1996. In 1995, 3,263,000 persons of all ages first smoked a cigarette; of these, 2,441,000 (74.8%) were aged less than 18 years. In 1996, 1,851,000 persons of all ages became daily smokers; of these, 1,226,000 (66.2%) were aged less than 18 years. If the incidence of initiation had not increased during 1988-1996, approximately 1,492,000 fewer persons aged less than 18 years would have been daily smokers by 1996.

Reported by: C Crump, L Packer, Research Triangle Institute, Research Triangle Park, North Carolina. J Gfroerer, Office of Applied Studies, Substance Abuse and Mental Health Svcs Administration. Office on Smoking and Health, National Center for Chronic Disease Prevention and Health Promotion; and an EIS Officer, CDC.

Editorial Note

Editorial Note: The findings in this report indicate that, during 1988-1996 among persons aged 12-17 years, the incidence of initiation of first use increased by 30% and of first daily use increased by 50%, more than 6000 persons aged less than 18 years try a cigarette each day, and more than 3000 persons aged less than 18 years become daily smokers each day. These findings are consistent with previous studies that suggest significant increases in smoking prevalence among U.S. adolescents since 1991 (5,6). Overall, these data show that public health gains observed during the 1970s and 1980s are being reversed.

The magnitude and patterns of the incidence calculated from the mid-1960s through the mid-1980s are generally consistent with those observed from a previous study (2). An estimated 1.1 million persons aged 20 years were regular smokers in 1985 (7), consistent with data from this study that showed 1.0 million persons aged less than 20 years became daily smokers in 1985

The findings of this report are subject to at least three potential limitations. First, differential mortality could have influenced the results for the earlier years of the study period because persons who become smokers, especially at a young age, experience higher death rates than persons who do not (2). Second, some persons either may have forgotten that they had ever smoked or reported that initiation occurred more recently than it actually did (2). Third, some persons (especially younger respondents {8}) may not have disclosed smoking behavior because of concerns about social acceptability or fear of disclosure.

If trends continue, approximately 5 million persons aged less than 18 years will die eventually from a smoking-attributable disease (9). Data on the comprehensive tobacco prevention and control programs in California and Massachusetts indicate that the recent pattern of increases in youth smoking rates can be attenuated (10). Efforts to reduce smoking initiation can be enhanced by further research on the interactions of factors such as tobacco product marketing, distress, and the drug effects of nicotine. Although primary prevention is the major goal of programmatic efforts, immediate cessation is critically important for adolescents (8). Tobacco-use prevention activities should include increasing tobacco prices; reducing the access to, and appeal of, tobacco products; conducting mass media campaigns and school-based tobacco use prevention programs; increasing provision of smoke-free indoor air; decreasing tobacco use by parents, teachers, and influential role models; developing and disseminating effective youth smoking cessation programs; and increasing support and involvement from parents and schools (8).

References

1. CDC. Reducing the health consequences of smoking: 25 years of progress -- a report of the Surgeon General. Rockville, Maryland: US Department of Health and Human Services, Public Health Service, CDC, 1989; DHHS publication no. (CDC)89-8411.

2. Substance Abuse and Mental Health Services Administration. Trends in the incidence of drug use in the United States, 1919-1992. Rockville, Maryland: US Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies, 1996; DHHS publication no. (SMA)96-3076.

3. Substance Abuse and Mental Health Services Administration. Preliminary results from the 1997 National Household Survey on Drug Abuse. Rockville, Maryland: US Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies, Division of Population Surveys, 1998; DHHS publication no. (SMA)98-3251.

4. Shah BV, Barnwell BG, Bieler GS. SUDAAN: software for the statistical analysis of correlated data: user's manual, release 7.0. Research Triangle Park, North Carolina: Research Triangle Institute, 1996.

5. CDC. Tobacco use among high school students -- United States, 1997. MMWR 1998;47:229-33.

6. Johnston LD, O'Malley PM, Bachman JG. National survey results on drug use from the Monitoring the Future study, 1975-1997. Volume I: secondary school students. Rockville, Maryland: US Department of Health and Human Services, Public Health Service, National Institutes of Health, National Institute on Drug Abuse, 1998; NIH publication no. 98-4345.

7. Pierce JP, Fiore MC, Novotny TE, Hatziandreu EJ, Davis RM. Trends in cigarette smoking in the United States: projections for the year 2000. JAMA 1989;261:61-5.

8. CDC. Preventing tobacco use among young people: a report of the Surgeon General. Atlanta, Georgia: US Department of Health and Human Services, Public Health Service, CDC, 1994.

9. CDC. Projected smoking-related deaths among youth -- United States. MMWR 1996;45:971-4.

10. Chaloupka FJ, Grossman M. Price, tobacco control policies, and youth smoking. Cambridge, Massachusetts: National Bureau of Economic Research, September 1996 (National Bureau of Economic Research Working Paper Series, no. 5740).

* Differences between estimates were considered statistically significant if the 95% CIs did not overlap. Use of trade names and commercial sources is for identification only and does not imply endorsement by CDC or the U.S. Department of Health and Human Services.

** For example, a 34-year-old person who was surveyed in 1994 and first smoked a cigarette at age 15 years in 1975 would have been 5 years old in 1965 and would have contributed person-years from 1965 to 1975. From 1965 through 1974, exposure time was 1 for each year. For 1975, exposure time was 0.5 (this assumes that persons initiate, on average, midway through the year). For subsequent years, exposure time was 0.

TABLE 1. Estimated annual age-specific incidence* of first use and of first daily use of
cigarettes among persons aged 12-17 years and 18-25 years, by year and age group
-- United States, 1965-1996
=============================================================================================================
                           First use                                         First daily use
            ---------------------------------------------      --------------------------------------------
                 12-17 years             18-25 years               12-17 years              18-25 years
            --------------------     --------------------      -------------------      -------------------
Year        Incidence  (95% CI+)     Incidence  (95% CI)       Incidence (95% CI)       Incidence (95% CI)
-----------------------------------------------------------------------------------------------------------
1965          101.3    (+/-14.9)       112.9    (+/-27.2)         44.0   (+/-14.1)        106.2   (+/-22.7)
1966           88.3    (+/-14.3)       125.4    (+/-28.4)         42.6   (+/- 9.6)        117.0   (+/-27.2)
1967          112.9    (+/-14.5)       114.6    (+/-21.8)         48.1   (+/-11.6)        100.8   (+/-25.3)
1968          101.6    (+/-16.5)       114.6    (+/-22.0)         49.7   (+/-11.6)        155.2   (+/-28.4)
1969          111.0    (+/-15.5)       122.3    (+/-24.3)         57.1   (+/-12.2)        116.4   (+/-24.3)
1970          113.7    (+/-17.8)       112.9    (+/-22.1)         52.5   (+/-10.0)        101.9   (+/-20.6)
1971          119.3    (+/-15.3)       102.1    (+/-21.6)         58.0   (+/-11.0)        117.9   (+/-23.7)
1972          129.6    (+/-14.7)       107.9    (+/-19.8)         57.7   (+/-10.0)         95.4   (+/-17.6)
1973          114.8    (+/-13.5)        87.2    (+/-15.1)         65.3   (+/-13.1)        106.5   (+/-19.4)
1974          132.2    (+/-15.9)        84.3    (+/-19.4)         66.2   (+/-11.8)        109.2   (+/-21.0)
1975          125.0    (+/-15.1)        95.7    (+/-18.8)         49.4   (+/- 7.8)         87.1   (+/-18.0)
1976          124.8    (+/-14.5)        87.6    (+/-19.4)         54.8   (+/- 8.2)         93.1   (+/-16.5)
1977          126.9    (+/-11.8)        87.8    (+/-18.4)         66.8   (+/-10.0)        108.0   (+/-22.5)
1978          112.0    (+/- 9.4)        72.7    (+/-12.9)         59.6   (+/- 7.6)         88.1   (+/-15.1)
1979          111.0    (+/-11.2)        83.8    (+/-17.4)         54.7   (+/-17.8)         92.5   (+/-13.7)
1980          105.1    (+/- 9.6)        70.0    (+/-12.9)         51.6   (+/- 6.7)         81.7   (+/-13.5)
1981          107.0    (+/-10.2)        66.7    (+/-12.5)         56.4   (+/- 7.6)         73.3   (+/-14.5)
1982          102.4    (+/- 9.2)        67.2    (+/-12.9)         49.2   (+/- 6.7)         73.3   (+/-15.3)
1983          106.0    (+/-10.4)        64.5    (+/- 9.4)         43.8   (+/- 6.3)         73.9   (+/-12.0)
1984           99.4    (+/- 9.0)        71.1    (+/-11.2)         52.3   (+/- 7.1)         65.4   (+/- 7.8)
1985          111.3    (+/-10.2)        69.4    (+/- 7.8)         50.2   (+/- 7.4)         66.2   (+/-10.0)
1986          107.0    (+/-11.2)        77.2    (+/-11.2)         56.7   (+/- 7.6)         69.5   (+/- 9.0)
1987           98.6    (+/- 9.6)        66.1    (+/- 9.2)         51.8   (+/- 9.2)         68.0   (+/- 9.8)
1988          107.0    (+/-10.0)        58.6    (+/- 9.0)         51.2   (+/- 7.4)         60.8   (+/- 8.8)
1989           99.5    (+/- 9.4)        60.9    (+/- 8.6)         53.8   (+/- 6.9)         61.4   (+/- 8.8)
1990          101.6    (+/- 8.0)        71.3    (+/-10.2)         57.8   (+/- 7.1)         63.6   (+/- 8.6)
1991          100.5    (+/- 8.8)        66.4    (+/-11.0)         57.6   (+/- 7.4)         58.0   (+/- 8.4)
1992          115.0    (+/- 8.2)        64.7    (+/- 8.8)         61.9   (+/- 7.8)         69.1   (+/- 8.2)
1993          121.4    (+/- 9.8)        70.1    (+/- 9.6)         58.7   (+/- 6.3)         60.0   (+/- 8.4)
1994&         131.0    (+/-12.9)        82.0    (+/-14.3)         67.7   (+/- 7.3)         68.9   (+/-11.6)
1995@         139.1    (+/-17.8)        85.8    (+/-19.8)         71.8   (+/- 8.8)         62.3   (+/-12.7)
1996**         NA++                       NA                      77.0   (+/-13.7)         68.4   (+/-15.3)
-----------------------------------------------------------------------------------------------------------
 * Per 1000 person-years of exposure.
 + Confidence interval.
 & Estimated using 1995, 1996, and 1997 data only.
 @ Estimated using 1996 and 1997 data only.
** Estimated using 1997 data only.
++ Not available.

Source: Substance Abuse and Mental Health Services Administration, National Household
Survey on Drug Abuse for 1994-1997 (3).
=============================================================================================================

Disclaimer   All MMWR HTML versions of articles are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the electronic PDF version and/or the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.

Page converted: 11/10/98

HOME  |  ABOUT MMWR  |  MMWR SEARCH  |  DOWNLOADS  |  RSS |  CONTACT POLICY  |  DISCLAIMER  |  ACCESSIBILITY

Morbidity and Mortality Weekly Report Centers for Disease Control and Prevention 1600 Clifton Rd, MailStop E-90, Atlanta, GA 30333, U.S.A Department of Health and Human Services

This page last reviewed 5/2/01