One of the 10 leading health indicators
that reflect the major health concerns in the United States is cigarette smoking
among adolescents. To examine changes in cigarette smoking among high school
students in the United States from 1991 to 1999, the Centers for Disease Control
and Prevention (CDC) analyzed data from the national Youth Risk Behavior Survey
(YRBS). This report summarizes the results of the analysis and indicates that
current smoking among high school students in the United States increased
significantly from 27.5% in 1991 to 34.8% in 1999; however, the analysis also
suggested that later in the decade, current smoking may have leveled or possibly
begun to decline.
The YRBS measures the prevalence of health-risk behaviors among
adolescents through representative biennial national, state, and local surveys.
The 1991, 1993, 1995, 1997, and 1999 national surveys used independent,
three-stage cluster samples to obtain cross-sectional data representative of
students in grades 9 through 12 in the 50 states and the District of Columbia.
In 1991, 1993, 1995, 1997, and 1999, the respective sample sizes were 12,272,
16,296, 10,904, 16,262, and 15,349; school response rates were 75%, 78%, 70%,
79%, and 77%; student response rates were 90%, 90%, 86%, 87%, and 86%; and
overall response rates were 68%, 70%, 60%, 69%, and 66%.
For each cross-sectional survey, students completed an
anonymous, self-administered questionnaire that included identically worded
questions about cigarette smoking. Lifetime smoking was defined as having ever
smoked cigarettes, even one or two puffs. Current smoking was defined as smoking
on ³ 1 of the 30 days preceding the survey. Frequent
smoking was defined as smoking on ³ 20 of the 30
days preceding the survey. Data are presented only for non-Hispanic black,
non-Hispanic white, and Hispanic students because the numbers of students from
other racial/ethnic groups were too small for meaningful analysis.
Data were weighted to provide national estimates; SUDAAN was
used for all data analysis. Secular trends were analyzed using logistic
regression analyses that controlled for sex, race/ethnicity, and grade and that
simultaneously assessed linear and quadratic time effects. Quadratic trends
suggest a significant but nonlinear trend in the data over time. When a
significant quadratic trend accompanies a significant linear trend, the data
demonstrate some nonlinear variation (eg, leveling or change in direction) in
addition to a linear trend.
Linear Trend Found for 10th-Grade Students
The prevalence of lifetime smoking remained stable from 1991 to
1999 among high school students overall and among all sex, racial/ethnic, and
grade subgroups except 10th-grade students. In 1999, 70.4% (95% confidence
interval [CI] = ± 3.0%) of all students reported lifetime smoking. Among
10th-grade students, lifetime smoking showed a significant linear trend from
1991 (68.3% [95% CI = ± 3.31%) to 1999 (73.9% [95% CI = ± 4.11%).
From 1991 to 1999, current smoking exhibited a significant
linear trend among students overall and among all sex, racial/ethnic, and grade
subgroups (Table 1). The overall prevalence of current smoking was 27.5%
in 1991 and 34.8% in 1999. A simultaneous quadratic trend was identified for
students overall, suggesting a leveling or possible decline in current smoking.
The male, black, black male, and 9th-grade student subgroups also showed this
simultaneous quadratic trend.
Each year, white students were significantly more likely than
Hispanic students, who were significantly more likely than black students, to
report current smoking (except in 1995 when white and Hispanic students were
equally likely to report current smoking, but both were significantly more
likely than black students to report this behavior). In 1991, white students
were 2.5 times more likely than black students and 1.2 times more likely than
Hispanic students to report current smoking. In 1999, white students were 2.0
times more likely than black students and 1.2 times more likely than Hispanic
students to report current smoking.
The prevalence of frequent smoking showed a significant linear
trend from 1991 to 1999 among students overall and in all sex, racial/ethnic,
and grade subgroups, except for Hispanic female students. The overall prevalence
of frequent smoking was 12.7% (95% CI = ± 2.2) in 1991 and 16.8% (95% CI = ±
2.5) in 1999. Among Hispanic female students, the prevalence of frequent smoking
remained stable from 1991 to 1999. For each of the five surveys, white students
were significantly more likely than black and Hispanic students to report this
Editorial Note From the CDC
Despite a leveling or possible decline in current smoking among
youth overall during the late 1990s, this trend may have been limited to
selected groups (ie, male, black, black male, and 9th-grade students). In
addition, frequent smoking rates overall and in all sex, racial/ethnic, and
grade subgroups (except Hispanic females) were significantly higher in 1999 than
in 1991 and showed no pattern of leveling or declining.
Additional research is needed to understand how current smoking
rates and secular changes in these rates vary among racial/ethnic groups. For
example, throughout the decade, the YRBS and other national surveys found that
black high-school students smoked at lower rates than white and Hispanic
high-school students; however, the 1999 National Youth Tobacco Survey reported
that current smoking rates among black middle-school students were similar to
rates among white and Hispanic middle-school students.
Among grade subgroups, data for 9th-grade students suggested a
leveling or possible decline in current smoking. Current smoking among
12th-grade students continued to rise each year. A previous study suggested that
current smoking peaked among 10th- and 12th-grade students in 1996 and 1997,
respectively. It is unclear whether future YRBS data will show a delayed peak
among 10th- and 12th-grade students.
Limitations of Findings
The findings in this report are subject to at least three
limitations. First, these data apply only to adolescents who attend high school.
In 1998, 5% of persons aged 16 to 17 years were not enrolled in a high school
program and had not completed high school. Second, the extent of underreporting
or overreporting in the YRBS cannot be determined, although the survey questions
demonstrate good test-retest reliability. Finally, using only five data points
makes it possible to characterize trends over the decade but difficult to
accurately characterize the direction current smoking will take during the next
Reducing the prevalence of current smoking among adolescents to
16% is one of the goals of the Leading Health Indicators. Achieving this goal by
2010 will require a 54% reduction in current smoking among adolescents
nationwide. Data from Florida, where comprehensive tobacco-control programs have
been initiated, suggest such declines are possible. From 1998 to 2000 in
Florida, current smoking declined 40% among middle school students and 18% among
high school students.
The CDC recommends that communities fully implement its
"Best Practices for Comprehensive Tobacco Control Programs" by
establishing comprehensive, sustainable, and accountable tobacco-control
programs. In addition, communities should follow the CDC’s "Guidelines
for School Health Programs to Prevent Tobacco Use and Addiction," which
recommend implementing school-based tobacco-use prevention programs in grades K-12,
with intensive instruction in grades 6-8, and supporting cessation efforts for
nicotine-dependent students. Finally, comprehensive tobacco-control programs
should also reduce the appeal of tobacco products, implement mass media
campaigns, increase tobacco excise taxes, implement policy and regulation of
tobacco products, and reduce youth access to tobacco products.
This commentary was reported by the Office on Smoking and
Health, and Division of Adolescent and School Health, National Center for
Chronic Disease Prevention and Health Promotion, CDC. Adapted from Morbidity and
Mortality Weekly Report 49(33):755-758, 2000.