Youth Substance  Use: State Estimates From the 1999 National Household Survey on Drug Abuse

Appendix H: Other Sources of Data

A variety of other surveys and data systems collect data on substance use. It is useful to consider the results of these other studies when discussing the National Household Survey on Drug Abuse (NHSDA) data. In doing this, it is important to understand the methodological differences between the different surveys and the impact that these differences could have on estimates of substance use prevalence. This appendix briefly describes several of these other data systems, including results from them.

In-depth comparisons have been done of the methodologies of the three major federally sponsored national surveys of substance use by youths (i.e., the NHSDA, the Monitoring the Future [MTF] study, and the Youth Risk Behavior Survey [YRBS]). In 1997, a comparison between the NHSDA and the MTF was published (Gfroerer et al., 1997). And in 1999, a series of papers comparing different aspects of the three national surveys was commissioned by the U.S. Department of Health and Human Services (DHHS), Office of the Assistant Secretary for Planning and Evaluation. Experts in survey methods for the latter effort reported the following findings:

• The design, implementation, and documentation of all three surveys are of high quality. The surveys exhibit no flaws in the execution of basic survey procedures.

• The goals and approaches of these three surveys are very different, making comparisons between them difficult. The surveys differ significantly in terms of populations covered, sampling methods, mode of data collection, questionnaires, and estimation methods.

• Estimates of substance use are generally highest from the YRBS and lowest from the NHSDA. The NHSDA probably produces lower rates because it is done in the home, whereas the other two surveys collect data in school classrooms, away from parents and other family members.

• NHSDA prevalence rates may also be lower because of the NHSDA's requirement of thorough parental consent prior to youth participation. The greater parental involvement in consent procedures in the NHSDA, compared with the two school surveys, may suppress reporting by youths of substance use.

Monitoring the Future (MTF). The MTF is a national survey that tracks drug use trends and related attitudes among America's adolescents. This survey is conducted annually by the Institute for Social Research at the University of Michigan through a grant awarded by the National Institute on Drug Abuse (NIDA). The MTF is composed of three substudies: (a) an annual survey of high school seniors initiated in 1975; (b) ongoing panel studies of representative samples from each graduating class that have been conducted by mail since 1976; and (c) annual surveys of 8th and 10th graders initiated in 1991. In 2000, for all three grades combined, there were 435 public and private schools and almost 45,200 students in the sample. The senior sample included 13,286 seniors in 134 public and private schools. As noted on the MTF website, in 2000 the 10th grade sample involved 14,576 students from 145 schools, and the 8th grade sample size was 17,311 students from 156 schools (MTF, 2000).

Comparisons between the MTF and students sampled in the NHSDA have generally shown NHSDA substance use prevalence levels to be lower than MTF estimates, with relative differences being largest for 8^th graders. However, the direction of trends has generally been similar between the two surveys. Both surveys showed significant increases in illicit drug use among adolescents between 1992 and 1996. The lower prevalences in the NHSDA may be due to more underreporting in the household setting as compared to the MTF school setting. MTF does not survey dropouts, a group generally shown (using the NHSDA) to have higher rates of use (Gfroerer et al., 1997). Data released in December 1999 from the MTF indicated drug use among adolescents generally held steady between 1998 and 1999. Levels of drug use showing little change included marijuana, cocaine, amphetamines, hallucinogens, tranquilizers, and heroin. Exceptions to this stability were seen for the use of MDMA ("ecstasy"), which increased in 1999 among 10^th and 12^th graders and anabolic steroid use increased among males in both 8^th and 10^th grades.

Youth Risk Behavior Survey (YRBS). The YRBS is a component of CDC's Youth Risk Behavior Surveillance System, which biennially measures the prevalence of six priority health risk behavior categories: (1) behaviors that contribute to unintentional and intentional injuries, (2) tobacco use, (3) alcohol and other drug use, (4) sexual behaviors that contribute to unintended pregnancy and sexually transmitted diseases (STDs), (5) unhealthy dietary behaviors, and (6) physical inactivity. The 1999 national school-based survey used a three-stage cluster sample design to produce a nationally representative sample of students in grades 9 through 12. The 1999 State and local surveys used a two-stage cluster sample design to produce representative samples of students in grades 9 through 12 in their jurisdictions (CDC, 2000a). The 1999 national YRBS sample included 15,349 students in grades 9 through 12 in the 50 States and DC. Data from the most recent YRBS indicated a general leveling of drug and alcohol use between 1997 and 1999. The 1999 data showed steady prevalence levels for both current marijuana and current alcohol use among 9^th through 12^th graders.

National Longitudinal Study of Adolescent Health (Add Health). In 1994-96, Add Health was conducted to measure the effects of family, peer group, school, neighborhood, religious institution, and community influences on such health risks as tobacco, drug, and alcohol use. The survey also asked about substance abuse (alcohol, tobacco, and illicit drugs). The survey consisted of three phases. First, roughly 90,000 students from grades 7 through 12 at 145 schools around the United States answered brief questionnaires. Next, interviews were conducted with about 20,000 students and their parents in the students' homes. Then, 1 year later, the students were interviewed a second time in their homes. Survey results indicated that nearly one third of teenagers had smoked marijuana; moreover, 6.9 percent of 7^th and 8^th graders used marijuana at least once in the past month as did 15.7 percent of 9^th through 12^th graders (Resnick et al., 1997).

Partnership Attitude Tracking Study (PATS). In November 1999, the Partnership for a Drug-Free America (PDFA) released results from the 1999 PATS, the only ongoing national research that tracks drug use and drug related attitudes among children as young as 8 and 9 years old, teenagers, and their parents. The 1999 study found significant changes in youths' acceptance and approval of drugs (PDFA, 2000). For example, the belief that "most people will try marijuana sometimes" declined from 40 percent in 1998 to 35 percent in 1999. Also, significantly more youths reported hearing or seeing anti-drug commercials every day or more (rising from 32 percent in 1998 to 45 percent in 1999). PATS found drug use to be significantly lower among youths who learned a great deal about drugs at home. In 1999, more than half (57 percent) of all parents said they spoke with their children about drugs at least four times in the past year, a significant increase from 44 percent of parents in 1998. Marijuana use declined among youths surveyed with results from the 1999 survey indicating lifetime trial of marijuana use among youths in grades 7 through 12 was 41 percent, down from 42 percent in 1998 and 44 percent in the 1997 survey. Trial marijuana use had been 29 percent in 1993. Past month marijuana use was 24 percent in 1997 and 21 percent in 1999. It had been 14 percent in 1993.

National Health Interview Survey (NHIS). The NHIS is a continuing nationwide sample survey that collects data using personal household interviews. In 1997, the data collection methodology changed from paper-and-pencil questionnaires to a computer-assisted personal interviewing (CAPI) instrument. The 1998 NHIS was conducted by the Bureau of the Census for the National Center for Health Statistics (NCHS). The survey estimated that 24.0 percent of the population age 18 and over were current cigarette smokers in 1998. Among males, 25.9 percent reported current cigarette smoking compared to 22.1 percent of females aged 18 or older. Current smokers are defined as those who have smoked at least 100 cigarettes in their lifetime and answer that they currently smoke, including those who smoke only on some days. The current smoker definition used in the NHIS is somewhat different from that used in the NHSDA where current cigarette smoking is defined as any use in the past month.

Monitoring the Future (MTF). This school-based survey showed increases in smoking rates among students from 1991 to 1996. Cigarette smoking peaked in 1996 among 8^th and 10^th graders nationwide and in 1997 among 12^th graders. Since those peak years, cigarette use has gradually declined. Current (past month) smoking rates found for 8^th graders were 14.3 percent in 1991, 21.0 percent in 1996, 19.4 percent in 1997, 19.1 percent in 1998, and 17.5 percent in 1999. Among 10^th graders, current smoking rates were 20.8 percent in 1991, 30.4 percent in 1996, 29.8 percent in 1997, 27.6 percent in 1998, and 25.7 percent in 1999. For 12^th graders, smoking rates rose steadily from 28.3 percent in 1991 to 36.5 percent in 1997 but then declined (not significantly) to 34.6 percent in 1999 (NIDA, 2000). More recent data indicated that cigarette use among adolescents declined sharply between the last two MTF surveys (MTF, 2000). For example, current smoking decreased significantly among 8^th graders, falling from 17.5 percent in 1999 to 14.6 percent in 2000. Past month cigarette use also declined sharply among 12^th graders, dropping from 34.6 percent in 1999 to 31.4 percent in 2000. Daily smoking in the past month declined from 15.9 to 14.0 percent among 10^th graders and from 23.1 to 20.6 percent among 12^th graders. The proportion of 10^th graders smoking heavily (i.e., smoking a half-pack or more of cigarettes per day) decreased among 10^th graders from 7.6 percent in 1999 to 6.2 percent in 2000 and among 12^th graders from 13.2 percent in 1999 to 11.3 percent in 2000. Prevalence rates for the use of smokeless tobacco remained stable.

The MTF data have indicated alcohol use among youths to be fairly stable over the past several years. Alcohol consumption in the month prior to survey was reported by 24 percent of 8^th graders, 40 percent of 10^th graders, and 51 percent of 12^th graders in the 1999 survey (NIDA, 2000). Binge drinking, defined in the MTF as consuming five or more drinks in a row sometime in the prior 2 weeks, also remained steady over the past several years. In the 1999 MTF, binge drinking rates stood at 15.2 percent, 25.6 percent, and 30.8 percent among 8^th, 10^th, and 12^th graders, respectively. Alcohol use among youths generally remained unchanged between 1999 and 2000. The MTF data indicated that alcohol use among youths remained fairly stable since the early 1990s. Alcohol consumption in the month prior to the 2000 survey was reported by 22.4 percent of 8^th graders, 41 percent of 10^th graders, and 50 percent of 12^th graders. Binge drinking also remained steady over the past 2 or 3 years of the survey. The latest binge drinking rates stand at 14.1 percent, 26.2 percent, and 30.0 percent among 8^th, 10^th, and 12^th graders, respectively (MTF, 2000).

Youth Risk Behavior Survey (YRBS). The YRBS found increases in longer trends for current cigarette use among students in grades 9 to 12. Current smoking rose from 27.5 percent in 1991 to 34.8 percent in 1999 (CDC, 2000a). Overall, lifetime, current, and frequent cigarette use prevalence (defined as smoking on 20 or more days of the 30 days preceding the survey) in the 1999 survey were 70.4, 34.8, and 16.8 percent, respectively. Although the NHSDA trend for smoking among youths (aged 12 to 17) has not shown these increases, the NHSDA estimates for years prior to 1994 were apparently substantial underestimates because the data were collected without private self-administered answer sheets. When the NHSDA converted to the use of these answer sheets in 1994, the smoking rate for adolescents approximately doubled. This raises questions about the accuracy of the NHSDA measurement of the trend prior to 1994, even after adjustments are made to account for the effect of the new questionnaire.

In general, the school-based YRBS has found higher rates of alcohol, cigarette, marijuana, and cocaine use among youths than those found in the NHSDA. Data from the most recent YRBS indicated a general leveling of alcohol use between 1997 and 1999. The 1999 data showed steady prevalence rates for current alcohol use among 9^th through 12^th graders. In fact, alcohol use among 9^th through 12^th graders in the YRBS remained fairly stable over the last few surveys. The prevalence of current alcohol use was 50 percent in the 1999 survey, which was consistent with the estimate of 50.8 percent in the 1991 YRBS (CDC, 2001). Episodic heavy drinking (defined as having five or more drinks on one or more occasions on 1 or more days in the 30 days prior to the survey) also held steady with prevalence rates of 31.3 percent in 1991 and 31.5 percent in 1999.

National Youth Tobacco Survey (NYTS). The American Legacy Foundation released findings from its 1999 NYTS in October 2000. The 1999 NYTS was designed to get data on tobacco-related issues for a nationally representative sample of students in grades 6 through 12. The survey was given to over 15,000 students in 131 school across the United States in the fall of 1999. The students completed anonymous, self-administered questionnaires that included a variety of tobacco-related questions. Major topic are covered by the 1999 NYTS included patterns of tobacco use, knowledge and attitudes about tobacco, minors' ability to purchase tobacco products, and exposure to environmental tobacco smoke (ETS). The American Legacy Foundation found that in 1999, approximately 7.3 percent of all adolescents were established smokers (they had smoked at least 100 cigarettes in their lifetime) (American Legacy Foundation, 2000).

College Alcohol Study (CAS). The Harvard School of Public Health's CAS is an ongoing survey supported by a grant from the Robert Wood Johnson Foundation. It surveys more than 15,000 students (18 to 24 years of age) at 140 four-year colleges in 40 States. The objective of the CAS is to look at high risk behaviors and to identify student- and college-level factors associated with these behaviors among college students. These behaviors include heavy episodic or binge drinking, smoking, illicit drug use, gun possession, violence, and other behavioral, social, and health-related problem facing America's college students today. The principal investigator is Henry Wechsler.

The CAS includes all forms of tobacco use: cigarettes, cigars, pipes, and smokeless tobacco. The prevalence of cigarette smoking by college students, which was sharply up between 1993 and 1997, stabilized between 1997 and 1999 (Harvard School of Public Health, 2000). In the 1999 CAS, a total of 14,138 students in 119 four-year colleges were surveyed. The 1999 data indicated that nearly half of all respondents (45.7 percent) had used a tobacco product in the past year, and one third (32.9 percent) had used a tobacco product in the past month (current use). Cigarettes accounted for most of the tobacco use (28.5 percent of the 18- to 24-year-old college students had smoked cigarettes in the 30 days prior to survey). Cigar use was also substantial with 37.1 percent citing lifetime use, 23.0 percent reporting past year use, and 8.5 percent saying they were current cigar users. Among college students, men were significantly more likely than females to be tobacco users and tobacco use was significantly higher among white students as compared to African-American, Hispanic, and Asian students.

Partnership Attitude Tracking Study (PATS). Data from the 1999 PATS showed declines in cigarette use among teenagers (see PDFA, 2000). For teenagers in grades 7 through 12, the prevalence of past month cigarette declined from 42 percent in 1998 to 37 percent in 1999. For those in grades 7 and 8, past month smoking declined from 36 percent in 1998 to 33 percent in 1999. Among 9^th and 10^th graders, the decline observed for past month cigarette use was from 44 percent in 1998 to 35 percent in 1999. For the oldest teenagers (those in grades 11 and 12), the decrease in past month cigarette use was from 47 percent in 1998 to 42 percent in 1999. The PDFA estimated that there were 23.6 million youths in grades 7 through 12. The 2000 PATS survey indicated that 80 percent of this population had tried alcohol at least once in their lives (PDFA, 2000).

Behavioral Risk Factor Surveillance System (BRFSS). This is a State-based telephone survey of the civilian, noninstitutionalized adult population. Adults include all persons aged 18 or older. In 1997, BRFSS surveyed all 50 states, the District of Columbia, and Puerto Rico and collected data on access to health care, health status indicators, health risk behaviors (including alcohol and cigarette use), and the use of clinical preventive services by State. In 1997, the median percentage of adults who reported current alcohol use was 54 percent (CDC, 2000b). By race/ethnicity, the median prevalence rate for this behavior was 55.4 percent, 40.4 percent, 50.8 percent, 50.5 percent, and 38.2 percent for whites, blacks, Hispanics, American Indians or Alaska Natives, and Asians or Pacific Islanders, respectively. Asians or Pacific Islanders were least likely to report binge drinking (i.e. consumption of five or more drinks on at least one occasion in the past month) and American Indians or Alaska Natives were most likely to report this behavior. The median percentage of adults reporting both having smoked 100 cigarettes or more in their lives and current cigarette use varied almost fourfold across the racial/ethnic groups. The median percentage for this behavior was 23.6 percent for whites, 22.8 percent for blacks, 23.1 percent for Hispanics, 41.3 percent for American Indians or Alaska Natives and 10.7 percent for Asians or Pacific Islanders.

National Longitudinal Study of Adolescent Health (Add Health). Results from the September 1994 to April 1995 of the National Longitudinal Study of Adolescent Health (Add Health described above) indicate that nearly 3.2 percent of 7^th and 8^th graders smoked six or more cigarettes a day as did 12.8 percent of 9^th through 12^th graders (Resnick et.al. 1997). In addition, 7.3 percent of 7^th and 8th graders used alcohol on 2 or more days in the past month as did 23.1 percent of 9^th through 12^th graders.

National Longitudinal Alcohol Epidemiologic Survey (NLAES). The NLAES was conducted by the U.S. Bureau of the Census for the National Institute on Alcohol Abuse and Alcoholism (NIAAA) in 1992. The NLAES was a multipurpose survey conducted to comply with NIAAA's mandate under the Anti-Drug Abuse Act of 1988, which emphasized the need to determine the incidence as well as the prevalence of alcohol use disorders (i.e., alcohol abuse and alcohol dependence) and their associated disabilities (including drug-specific abuse and dependence, major depression, and physical disorders). Face-to-face interviews were conducted with 42,862 respondents aged 18 or older in the contiguous United States. The NLAES studied the drinking practices, behaviors, and related problems in the general public. Its assessments included an extensive set of questions designed to assess the presence of symptoms of alcohol abuse and dependence during the prior 12 months based on criteria from the Diagnostic and Statistical Manual of Mental Disorders (APA, 1987, 1994). The NLAES estimated that 4.4 percent of adults were alcohol dependent and another 3.0 percent were classified as abusing alcohol, but not dependent, within the past year (NIAAA, 1995). In comparison, the 1999 NHSDA estimated that 3.7 percent of adults and 3.6 percent of youths aged 12 to 17 were dependent on alcohol. Rates of alcohol use disorder were found to be higher among males than females and highest in the youngest age cohort (18 to 29 years). Young nonblack males were almost twice as likely as young black males to have an alcohol use disorder.

The Parents' Resource Institute for Drug Education (PRIDE) Surveys. This survey series provides ongoing estimates of the use of alcohol and tobacco plus eight types of illegal drugs since the 1987-88 school year (PRIDE Surveys, 2001). Beginning in 1993-94, the PRIDE Questionnaire has also asked questions about deviant behaviors, such as carrying a gun to school, making and receiving threats, physical abuse, and joining gangs. The 1999-2000 survey was conducted during the school year and included students nationwide; however, the survey sample is not nationally representative and encompasses voluntary, self-selected students. The data are collected between August and June of each school year. The 1999-2000 survey indicated that 53.3 percent of students in grades 6 through 12 had used alcohol in the year prior to the survey and 23.9 percent had used alcohol in the past month. Prevalence of alcohol use declined significantly from 56.8 percent in the 1998-99 school year to 53.3 percent in the 1999-2000 (PRIDE Surveys, 2001).

Partnership Attitude Tracking Study (PATS). As noted earlier, in November 1999, the PDFA released results from the 1999 PATS, the only ongoing national research that tracks drug use and drug-related attitudes among children aged 9 to 11 as well as older teenagers. The study documented a gap between parents' perceptions about their children and drugs and what teenagers and children are actually experiencing (PDFA, 2000).

Washington, DC, Metropolitan Area Drug Study (DC*MADS). This study was designed to (a) estimate the prevalence, correlates, and consequences of drug abuse among all types of people residing in one metropolitan area of the country during one period of time and (b) to develop a methodological model for similar types of research in other metropolitan areas of the country. Sponsored by NIDA and fielded in 1991 and 1992, the project focused on hard-to-reach populations, such as adult and juvenile offenders, new mothers, and drug abuse treatment clients. DC*MADS provided a replicable methodological approach for developing representative estimates of the prevalence of drug abuse among all population subgroups, regardless of their residential setting, in a metropolitan area. The key domains in DC*MADS were homeless people, institutionalized persons, and the household population. A major finding of DC*MADS was that, when data are aggregated for populations from each of the three domains, the overall prevalence estimates for use of drugs differ only marginally from those that would be obtained from the household population alone (i.e., from the NHSDA). However, for some categories of drug users, the nonhousehold population was found to include a substantial proportion of users. About 25 percent of past year crack users, 20 percent of past year heroin users, and one third of past year needle users were found in the nonhousehold population (Bray & Marsden, 1999).

Worldwide Survey of Substance Abuse and Health Behaviors Among Military Personnel. The 1998 Worldwide Survey of Substance Abuse and Health Behaviors Among Military Personnel was sponsored by the Department of Defense and conducted by Research Triangle Institute (RTI) (). The survey interviewed 17,264 active-duty Armed Forces personnel worldwide. Military personnel generally exhibited lower rates of cigarette use than the civilian population, but this finding seemed largely due to an increase in smoking among civilians rather than significant decreases among military personnel or changes in the military population. Illicit drug use declined steadily and dramatically in the Military from 1980 to 1998, and this decrease was not explained by changes in the demographic composition of the Military. Rates of illicit drug use in the Military are significantly lower than those observed for the comparable civilian population when demographic differences between the Military and civilian populations are taken into account. Differences in illicit drug use between the military and civilian populations were more pronounced for males than females. For males aged 18 to 55, 2.8 percent of those in the Military used drugs in the 30 days prior to survey compared to 11.4 percent of the civilian population (civilian estimate adjusted for demographic differences). For females aged 18 to 55, 1.9 percent of those in the Military used drugs in the 30 days prior to survey compared to 6.2 percent of the civilian population (adjusted). This survey indicated that nearly all military personnel reported having been tested for drugs since joining the Military.

Surveys of Inmates in State and Federal Correctional Facilities. This 1997 surveys sampled inmates from a universe of 1,409 State prisons and 127 Federal Prisons for the Bureau of Justice Statistics (BJS, 1999). Systematic random sampling was used to select the inmates for computer-assisted personal interviewing (CAPI). The final numbers interviewed were 14,285 State prisoners and 4,041 Federal prisoners. Among other items, these surveys collected information on the use of drugs in the month before the offense for convicted inmates. Women in State prisons (62 percent) were more likely than men (56 percent) to have used drugs in the month before the offense. Women were also more likely to have committed their offense while under the influence of drugs (40 vs. 32 percent of male prisoners). Among Federal prisoners, men (45 percent) were more likely than women (37 percent) to have used drugs in the past month. Male and female Federal prisoners were equally likely to report the influence of drugs during their offense (23 percent of male and 19 percent of female prisoners). The survey results indicate substantially higher rates of drug use among State and Federal prisoners (BJS, 1999) as compared to the household population.

This page was last updated on June 03, 2008.

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