Results from the 2011 National Survey on Drug Use and Health: Summary of National Findings

Appendix C, D, E, Tables, Figures

Reprinted with permission of the Substance Abuse and Mental Health Services Administration www.SAMHSA.gov

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
Substance Abuse and Mental Health Services Administration
Center for Behavioral Health Statistics and Quality

Table of Contents

C. Other Sources of Data
C.1 Other National Surveys of Substance Use
C.2 Surveys of Populations Not Covered by NSDUH

D. References

E. List of Contributors

List of Figures
List of Tables

Appendix C: Other Sources of Data

There are sources of substance use data other than the National Survey on Drug Use and Health (NSDUH). It is useful to consider the results of these other studies when discussing NSDUH data because no single source of data can fully cover all issues associated with substance use in the United States. Each data source can contribute to a broader understanding of substance use and the relationships of substance use to other issues of interest. This appendix briefly describes several of these other data systems and presents selected comparisons with NSDUH results. In addition, this appendix describes surveys on substance use of populations not covered by NSDUH.

When evaluating the information presented here, it is important to consider and understand the methodological differences between the different surveys and the impact that these differences could have on estimates of the presence of substance use. Several studies have compared NSDUH estimates with estimates from other studies and have evaluated how differences may have been affected by differences in survey methodology (Gfroerer, Wright, & Kopstein, 1997b; Grucza, Abbacchi, Przybeck, & Gfroerer, 2007; Hennessy & Ginsberg, 2001; Miller et al., 2004). These comparisons suggest that the goals and approaches of surveys are often different, making comparisons between them difficult. Some methodological differences that have been identified as affecting comparisons include populations covered, sampling methods, modes of data collection, questionnaires, and estimation methods.

C.1 Other National Surveys of Substance Use

Behavioral Risk Factor Surveillance System (BRFSS)

The Behavioral Risk Factor Surveillance System (BRFSS)—a State-based system of health surveys—collects information on health risk behaviors, preventive health practices, and health care access primarily related to chronic disease and injury. The BRFSS surveys are cross-sectional telephone surveys conducted by State health departments with technical and methodological assistance from the Centers for Disease Control and Prevention (CDC). Every year, States conduct monthly telephone surveys of adults (aged 18 or older) in households using random-digit-dialing methods; persons living in group quarters (e.g., dormitories) are excluded. Since 1994, BRFSS has collected data from all 50 States, the District of Columbia, Puerto Rico, and the U.S. Virgin Islands using a computer-assisted telephone interviewing (CATI) design. More than 350,000 adults are interviewed each year. Beginning with the 2011 BRFSS, the sample design covers households using only cellular telephones. This change in coverage may affect estimates and comparability over time.

National estimates typically are presented as medians. BRFSS includes questions on alcohol consumption and tobacco use.

NSDUH and BRFSS rates of current alcohol use have been generally similar, but NSDUH has shown consistently higher rates of binge drinking than BRFSS. The use of audio computer-assisted self-interviewing (ACASI) in NSDUH, which is considered to be more anonymous and yields higher reporting of sensitive behaviors, was offered as an explanation for the lower binge rates in BRFSS (Miller et al., 2004). Because BRFSS uses CATI, it may yield lower reports of some sensitive behaviors than NSDUH, which employs face-to-face data collection with ACASI for questions about these behaviors. Response rates also are higher in NSDUH than BRFSS, which could have resulted in differential nonresponse bias patterns in the two surveys.

For further details, see the CDC Web site at https://www.cdc.gov/brfss/.

Monitoring the Future (MTF)

The Monitoring the Future (MTF) study is an ongoing study of substance use trends and related attitudes among America’s secondary school students, college students, and adults through age 50. The study is conducted annually by the Institute for Social Research at the University of Michigan through grants awarded by the National Institute on Drug Abuse (NIDA). The MTF and NSDUH are the Federal Government’s largest and primary tools for tracking youth substance use. 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 (i.e., 12th graders) that have been conducted by mail since 1976; and (c) annual surveys of 8th and 10th graders initiated in 1991. Each spring, students in the 8th, 10th, and 12th grades complete a self-administered, machine-readable questionnaire during a regular class period. Approximately 50,000 students in about 420 public and private secondary schools are surveyed annually for the cross-sectional study, and approximately 2,400 persons who participated in the survey of 12th graders are followed longitudinally. The latest MTF was conducted in 2011. The MTF provides information on the use of alcohol, illicit drugs, and tobacco.

Comparisons between the MTF estimates and estimates based on students sampled in NSDUH generally have shown NSDUH substance use prevalence levels to be lower than MTF estimates (Table C.1).³⁰ The lower prevalences in NSDUH may be due to more underreporting in the household setting as compared with the MTF school setting and some overreporting in the school settings. However, findings presented in Chapter 8 of this report generally show parallel trends in the prevalence of substance use in NSDUH and MTF for both the annual cross-sectional data for youths and the longitudinal data for young adults.

The MTF does not survey dropouts or include students who were absent from school on the day of the survey. NSDUH has shown dropouts to have higher rates of illicit drug use (Gfroerer et al., 1997b). Therefore, the population of inference for the MTF school-based data collection is adolescents who were in the 8th, 10th, and 12th grades. Depending on the effects of the exclusion of dropouts and frequent absentees, data from MTF may not generalize to the population of adolescents as a whole, especially for older adolescents. The dropout rates among public school students in the 2008 to 2009 school year were 3.2 percent for 9th graders, 3.5 percent for 10th graders, 3.8 percent for 11th graders and 6.0 percent for 12th graders (Stillwell, Sable, & Plotts, 2011). Although these rates appear to be low, students dropping out of school in each lower grade could have a cumulative effect on school-based survey estimates for adolescents in the higher grades.

For further details, see the MTF Web site at https://www.monitoringthefuture.org/.

National Comorbidity Survey (NCS)

The National Comorbidity Survey (NCS) was sponsored by the National Institute of Mental Health (NIMH), NIDA, and the W.T. Grant Foundation. It was designed to measure in the general population the prevalence of the illnesses described in the Diagnostic and Statistical Manual of Mental Disorders, 3rd edition revised (DSM-III-R) (American Psychiatric Association [APA], 1987). The first wave of the NCS was a household survey of persons in the continental United States (i.e., excluding Alaska and Hawaii) that collected data from 8,098 respondents aged 15 to 54 in a face-to-face interview using paper-and-pencil interviewing (PAPI). These responses were weighted to produce nationally representative estimates. A random sample of 4,414 respondents also was administered an additional module that captured information on nicotine dependence. The interviews took place between 1990 and 1992. The NCS used a modified version of the Composite International Diagnostic Interview (the University of Michigan-CIDI) to generate DSM-III-R diagnoses.

There have been several recent follow-ups to and replications of the original NCS, including a 10-year follow-up of the baseline sample (NCS-2), a replication study conducted in 2001 to 2003 with a newly recruited nationally representative sample of 9,282 respondents aged 18 or older (NCS-R) (Kessler et al., 2004), and an adolescent sample of adolescents aged 13 to 17 (NCS-A) in 2001 to 2004 that included 904 adolescents from households that participated in the NCS-R and 9,244 respondents from a nationally representative sample of 320 schools (Kessler et al., 2009). As for the NCS, the samples for the NCS-2, NCS-R, and NCS-A excluded Alaska and Hawaii.

The NCS provides information on the use of alcohol, illicit drugs, and tobacco and on substance dependence or abuse. The NCS-R used an updated version of the CIDI that was designed to capture diagnoses of substance abuse or dependence using current DSM-IV criteria (APA, 1994). Interviews were conducted using computer-assisted personal interviewing (CAPI). It should be noted that in several NCS-R studies (e.g., Kessler, Chiu, Demler, Merikangas, & Walters, 2005), the diagnosis for abuse also includes those who meet the diagnosis for dependence. In contrast, NSDUH follows DSM-IV guidelines and limits the definition of abuse to persons who do not meet the criteria for dependence. To make the NCS definition of abuse comparable with that of NSDUH, the rate for dependence must be subtracted from the rate for abuse. Rates of alcohol dependence or abuse and rates of illicit drug dependence or abuse were generally lower in NCS-R than in NSDUH (Kessler et al., 2005).

For further details, see the NCS Web site at https://www.hcp.med.harvard.edu/ncs/.

National Health and Nutrition Examination Survey (NHANES)

The National Health and Nutrition Examination Survey (NHANES) has assessed the health and nutritional status of children and adults in the United States since the 1960s through the use of both survey and physical examination components. It is sponsored by the National Center for Health Statistics (NCHS) and began as a series of periodic surveys in which several years of data were combined into a single data release. Since 1999, it has been a continuous survey, with interview data collected each year for approximately 5,000 persons of all ages. The target population for NHANES is the civilian, noninstitutionalized population regardless of age. Data for 2009-2010 are the most currently available for public use; 2 years of data are combined to protect respondent confidentiality.

NHANES interviews are conducted in respondents’ homes. NHANES also collects physical health measurements and data on sensitive topics through ACASI in mobile examination centers (MECs), which travel to locations throughout the United States. The NHANES MEC interview includes questions on alcohol, illicit drug, and tobacco use.

Both NSDUH and NHANES use complex cluster sample designs that affect the precision of estimates. In addition, the smaller sample sizes for NHANES (i.e., 5,000 per year vs. 67,500 per year for NSDUH) are likely to yield estimates that are less precise than those in NSDUH. The sources of nonresponse and coverage bias also differ for the two surveys. For example, NHANES respondents have to travel to a MEC to respond to the substance use items, which may eliminate homebound respondents or affect the participation of respondents with limited access to transportation.

Combined NHANES data from 1999 to 2004 indicated that 13.0 percent of youths aged 12 to 17 had smoked cigarettes in the past 30 days, 21.1 percent had used alcohol in the past 30 days, and 10.4 percent were past month binge alcohol users. An estimated 21.1 percent of youths had ever tried marijuana, and 2.4 percent had ever used cocaine (Fryar, Merino, Hirsch, & Porter, 2009). NSDUH estimates for youths aged 12 to 17 in 2002 to 2004 ranged from 11.9 to 13.0 percent for past month use of cigarettes, from 17.6 to 17.7 percent for past month alcohol use, and from 10.6 to 11.1 percent for past month binge alcohol use. Lifetime use of marijuana in 2002 to 2004 among youths ranged from 19.0 to 20.6 percent, and lifetime use of cocaine ranged from 2.4 to 2.7 percent.

For further details, see the NHANES Web site at https://www.cdc.gov/nchs/nhanes.htm.

National Health Interview Survey (NHIS)

The National Health Interview Survey (NHIS) is a continuous nationwide sample survey that collects data using personal household interviews through an interviewer-administered CAPI system. The survey is sponsored by the NCHS and provides national estimates of the health status and behaviors of the civilian, noninstitutionalized population, including cigarette smoking and alcohol use among persons aged 18 or older. NHIS data have been collected since 1957. In 2010, data were derived from three core components of the survey: the Family Core, which collects information from all family members aged 18 or older in each household; the Sample Adult Core, which collects information from one adult aged 18 or older in each family; and the Sample Child Core, which collects information on youths under age 18 from a knowledgeable family member, usually a parent, in households with a child. In 2010, NHIS data were based on 89,976 persons in the Family Core, 27,157 adults in the Sample Adult Core, and 11,277 children in the Sample Child Core (NCHS, Division of Health Interview Statistics, 2011).

For further details, see the NCHS Web site at https://www.cdc.gov/nchs/nhis.htm.

National Longitudinal Alcohol Epidemiologic Survey (NLAES) and National Epidemiologic Survey on Alcohol and Related Conditions (NESARC)

The National Longitudinal Alcohol Epidemiologic Survey (NLAES) was conducted in 1991 and 1992 by the U.S. Bureau of the Census for the National Institute on Alcohol Abuse and Alcoholism (NIAAA). Face-to-face, interviewer-administered interviews were conducted with 42,862 respondents aged 18 or older in the contiguous United States. Despite the survey name, the design was cross-sectional.

The National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) was conducted in 2001 and 2002, also by the U.S. Bureau of the Census for NIAAA, using a computerized interviewer-administered interview. The NESARC sample was designed to make inferences for persons aged 18 or older in the civilian, noninstitutionalized population of the United States, including Alaska, Hawaii, and the District of Columbia, and including persons living in noninstitutional group quarters. NESARC was designed to be a longitudinal survey. The first wave was conducted in 2001 and 2002, with a final sample size of 43,093 respondents aged 18 or older. The second wave was conducted in 2004 and 2005 (Grant & Dawson, 2006). A 1-year data collection period for the next wave of the survey (NESARC-III) began in 2012 with a new sample of approximately 46,500 adults.

The study contains assessments of drug use, dependence, and abuse and associated mental disorders. NESARC included an extensive set of questions, based on DSM-IV criteria (APA, 1994), designed to assess the presence of symptoms of alcohol and drug dependence and abuse in persons’ lifetimes and during the prior 12 months. In addition, DSM-IV diagnoses of major mental disorders were generated using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-version 4 (AUDADIS-IV), which is a structured diagnostic interview that captures major DSM-IV axis I and axis II disorders.

Research indicates that (a) prevalence estimates for substance use were generally higher in NSDUH than in NESARC; (b) rates of past year substance use disorder (SUD) for cocaine and heroin use were higher in NSDUH than in NESARC; (c) rates of past year SUD for use of alcohol, marijuana, and hallucinogens were similar between NSDUH and NESARC; and (d) prevalence estimates for past year SUD conditional on past year use were substantially lower in NSDUH for the use of marijuana, hallucinogens, and cocaine (Grucza et al., 2007). A number of methodological factors might have contributed to such discrepancies, including privacy and anonymity (questions about sensitive topics in NSDUH are self-administered, while similar questions are interviewer administered in NESARC, which may have resulted in higher use estimates in NSDUH) and differences in SUD diagnostic instrumentation (which may have resulted in higher SUD prevalence among past year substance users in NESARC).

For further details about NLAES, see Stinson et al. (1998). For an overview of NESARC findings, see Caetano (2006).

National Longitudinal Study of Adolescent Health (Add Health)

The National Longitudinal Study of Adolescent Health (Add Health) was conducted to measure the effects of family, peer group, school, neighborhood, religious institution, and community influences on health risks, such as tobacco, drug, and alcohol use. Add Health was initiated in 1994 and supported by grants from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) with cofunding from 21 other Federal agencies and foundations.

The study began in 1994-1995 (Wave I) with an in-school questionnaire administered to a nationally representative sample of students in grades 7 to 12 and followed up with an in-home interview. In Wave I, about 90,000 students in grades 7 to 12 were surveyed at 144 schools around the United States using brief, machine-readable questionnaires during a regular class period. Interviews also were conducted with about 20,000 students and their parents in the students’ homes using a combined CAPI and ACASI design. In Wave II, conducted in 1996, about 15,000 students in grades 8 to 12 were interviewed a second time in their homes. In Wave III in 2001-2002, about 15,000 of the original Add Health respondents, then aged 18 to 26, were reinterviewed to investigate how adolescent experiences and behaviors are related to outcomes during the transition to adulthood. Wave IV was conducted in 2007-2008 when the approximately 15,000 respondents were aged 24 to 32. The study provides information on the use of alcohol, illicit drugs, and tobacco.

For further details, see the Add Health Web site at https://www.cpc.unc.edu/projects/addhealth.

Partnership Attitude Tracking Study (PATS)

The Partnership Attitude Tracking Study (PATS), an annual national research study that tracks attitudes about illegal drugs, is sponsored by the Partnership at Drugfree.org and the MetLife Foundation. PATS consists of two nationally representative samples—a teenage sample for students in grades 9 through 12 and a parent sample. Adolescents complete self-administered, machine-readable questionnaires during a regular class period with their teacher remaining in the room. The latest PATS surveys of teenagers and parents were conducted in 2011. The 2011 survey of adolescents included questions about use of cigarettes, alcohol, and illicit drugs. In 2011, 3,322 teenagers were surveyed nationwide in the 23rd wave of the survey conducted since 1987, and 821 parents or caregivers of children in grades 9 to 12 were surveyed (Partnership at Drugfree.org & MetLife Foundation, 2012).

In general, NSDUH estimates of substance use prevalence for adolescents are lower than PATS estimates for youths in that age group. In 2011, for example, PATS estimates of marijuana use among adolescents in grades 9 through 12 were 47 percent for lifetime use and 27 percent for use in the past month (Partnership at Drugfree.org & MetLife Foundation, 2012). Corresponding estimates of marijuana use from NSDUH for grades 9 through 12 were 29.3 percent for lifetime use and 13.3 percent for past month use (Table C.2). The differences in prevalence estimates are likely to be due to the different study designs. The youth portion of PATS is a school-based survey, which may elicit more reporting of sensitive behaviors than the home-based NSDUH.

For further details, see the Partnership at Drugfree.org Web site at https://www.drugfree.org/.

Youth Risk Behavior Survey (YRBS)

The Youth Risk Behavior Survey (YRBS) is a component of the CDC’s Youth Risk Behavior Surveillance System (YRBSS), which measures the prevalence of six priority health risk behavior categories: (a) behaviors that contribute to unintentional injuries and violence; (b) tobacco use; (c) alcohol and other drug use; (d) sexual behaviors that contribute to unintended pregnancy and sexually transmitted diseases, including human immunodeficiency virus infection; (e) unhealthy dietary behaviors; and (f) physical inactivity. The YRBSS includes national, State, territorial, tribal, and local school-based surveys of high school students conducted every 2 years. The national school-based survey uses a three-stage cluster sample design to produce a nationally representative sample of students in grades 9 through 12 who attend public and private schools. The State and local surveys use a two-stage cluster sample design to produce representative samples of public school students in grades 9 through 12 in their jurisdictions. The YRBS is conducted during the spring, with students completing a self-administered, machine-readable questionnaire during a regular class period. The latest YRBS was conducted in 2011. For the 2011 national YRBS, 15,425 usable questionnaires were obtained in 158 schools.

In general, the YRBS school-based survey has found higher rates of substance use for youths than those found in NSDUH (Table C.2).³¹ The lower prevalence rates in NSDUH are likely due to the differences in study design. As in the case of comparisons with estimates from the MTF, the lower prevalences in NSDUH may be due to more underreporting in the household setting, as compared with the YRBS school setting, and some overreporting in the school settings.

Similar to other school-based surveys, the population of inference for the YRBS is the population of adolescents who are in school, specifically those in the 9th through 12th grades. Consequently, the YRBS does not include data from dropouts. The YRBS makes follow-up attempts to obtain data from youths who were absent on the day of survey administration, but nevertheless does not obtain complete coverage of these youths. For these reasons, YRBS data are not intended to be used for making inferences about the adolescent population of the United States as a whole.

For further details, see the CDC Web site at https://www.cdc.gov/HealthyYouth/yrbs/.

C.2 Surveys of Populations Not Covered by NSDUH

Department of Defense Survey of Health Related Behaviors Among Active Duty Military Personnel

The 2008 Department of Defense Survey of Health Related Behaviors Among Active Duty Military Personnel was the 10th in a series of studies conducted since 1980. The sample consisted of 28,546 active-duty Armed Forces personnel worldwide who anonymously completed self-administered questionnaires that assessed substance use and other health behaviors. Members of the Coast Guard were included for the first time in the 2008 survey (Bray et al., 2009). The 2011 survey was fielded in August 2011 and included onsite and Internet survey administrations (Assistant Secretary of Defense for Health Affairs, 2011). The survey provides information about the use of alcohol, illicit drugs, and tobacco.

In recent administrations of this survey, comparisons with NSDUH data have consistently shown that, even after accounting for demographic differences between the military and civilian populations, the military personnel had higher rates of heavy alcohol use than their civilian counterparts, similar rates of cigarette use, and lower rates of illicit drug use.

Surveys of Inmates in State and Federal Correctional Facilities (SISCF, SIFCF)

The Survey of Inmates in State Correctional Facilities (SISCF) and the Survey of Inmates in Federal Correctional Facilities (SIFCF) have provided nationally representative data on State prison inmates and sentenced Federal inmates held in federally owned and operated facilities. The Survey of State Inmates was conducted in 1974, 1979, 1986, 1991, 1997, and 2004, and the Survey of Federal Inmates in 1991, 1997, and 2004. The 2004 SISCF was conducted for the Bureau of Justice Statistics (BJS) by the U.S. Census Bureau, which also conducted the SIFCF for the BJS and the Federal Bureau of Prisons. Both surveys provide information about current offense and criminal history, family background and personal characteristics, prior drug and alcohol use and treatment, gun possession, and prison treatment, programs, and services. The surveys are the only national source of detailed information on criminal offenders, particularly special populations such as drug and alcohol users and offenders who have mental health problems. Systematic random sampling was used to select the inmates, and the 2004 surveys of State and Federal inmates were administered through CAPI. In 2004, 14,499 State prisoners in 287 State prisons and 3,686 Federal prisoners in 39 Federal prisons were interviewed.

Prior drug use among State prisoners remained stable on all measures between 1997 and 2004, while the percentage of Federal inmates who reported prior drug use rose on most measures (Mumola & Karberg, 2006). For the first time, half of Federal inmates reported drug use in the month before their offense. In 2004, measures of drug dependence and abuse based on criteria in DSM-IV (APA, 1994) were introduced, and 53 percent of the State and 45 percent of Federal prisoners met the DSM-IV criteria for drug abuse or dependence. The survey results indicate substantially higher rates of drug use among State and Federal prisoners as compared with NSDUH’s rates for the general household population.

For further details, see BJS’s “All Data Collections” Web page at https://bjs.ojp.usdoj.gov/index.cfm?ty=dca.

Table C.1 – Use of Specific Substances in Lifetime, Past Year, and Past Month among 8th, 10th, and 12th Graders in MTF and NSDUH: Percentages, 2010 and 2011
Drug/Current Grade Level	MTF Lifetime (2010)	MTF Lifetime (2011)	MTF Past Year (2010)	MTF Past Year (2011)	MTF Past Month (2010)	MTF Past Month (2011)	NSDUH Lifetime (2010)	NSDUH Lifetime (2011)	NSDUH Past Year (2010)	NSDUH Past Year (2011)	NSDUH Past Month (2010)	NSDUH Past Month (2011)
MTF = Monitoring the Future; NSDUH = National Survey on Drug Use and Health. — Not available. NOTE: NSDUH data have been drawn from January to June of each survey year and subset to persons aged 12 to 20 to be more comparable with MTF data. Some 2010 NSDUH estimates may differ from previously published estimates due to updates (see Section B.3 in Appendix B of this report). ^aDifference between estimate and 2011 estimate is statistically significant at the .05 level. ^bDifference between estimate and 2011 estimate is statistically significant at the .01 level. Sources: National Institute on Drug Abuse, Monitoring the Future Study, University of Michigan, 2010 and 2011. SAMHSA, Center for Behavioral Health Statistics and Quality, National Survey on Drug Use and Health, 2010 and 2011 (January-June).
Marijuana
8th Grade	17.3	16.4	13.7	12.5	8.0	7.2	8.3	8.7	7.1	6.6	3.1	3.3
10th Grade	33.4	34.5	27.5	28.8	16.7	17.6	27.4	27.5	22.1	23.2	10.9	11.3
12th Grade	43.8	45.5	34.8	36.4	21.4	22.6	37.6	39.8	29.9	30.5	17.1	18.0
Cocaine
8th Grade	2.6	2.2	1.6	1.4	0.6	0.8	0.8	0.4	0.4	0.2	0.1	0.0
10th Grade	3.7	3.3	2.2	1.9	0.9	0.7	2.7	1.9	2.0	1.4	0.3	0.5
12th Grade	5.5	5.2	2.9	2.9	1.3	1.1	3.8	3.5	2.6	2.4	0.6	0.9
Inhalants
8th Grade	14.5	13.1	8.1^a	7.0	3.6	3.2	10.1	8.9	4.8	4.1	1.4	1.2
10th Grade	12.0^b	10.1	5.7^b	4.5	2.0	1.7	9.3	9.5	3.9	3.5	0.7	0.5
12th Grade	9.0	8.1	3.6	3.2	1.4	1.0	7.5	6.7	3.2	1.8	0.6	0.1
Cigarettes
8th Grade	20.0	18.4	—	—	7.1	6.1	13.6	11.5	8.6	7.6	4.2	3.5
10th Grade	33.0^a	30.4	—	—	13.6^a	11.8	29.8	28.2	21.5	19.6	12.2	11.4
12th Grade	42.2^a	40.0	—	—	19.2	18.7	42.2	42.4	31.6	30.8	21.9	21.8
Alcohol
8th Grade	35.8^b	33.1	29.3^a	26.9	13.8	12.7	23.4	22.9	17.4	16.0	6.9	6.0
10th Grade	58.2^a	56.0	52.1^a	49.8	28.9	27.2	50.2	48.6	42.0	41.0	18.8	19.9
12th Grade	71.0	70.0	65.2	63.5	41.2	40.0	69.5^a	64.5	60.3	56.9	33.8	34.5

Table C.2 – Lifetime and Past Month Substance Use among Students in Grades 9 to 12 in YRBS and NSDUH: Percentages, 2005, 2007, 2009, and 2011
Substance/Period of Use	YRBS (2005)	YRBS (2007)	YRBS (2009)	YRBS (2011)	NSDUH (2005)	NSDUH (2007)	NSDUH (2009)	NSDUH (2011)
NSDUH = National Survey on Drug Use and Health; YRBS = Youth Risk Behavior Survey. — Not available. NOTE: NSDUH data have been drawn from January to June of each survey year and subset to persons aged 12 to 20 to be more comparable with YRBS data. Some 2007 and 2009 NSDUH estimates may differ from previously published estimates due to updates (see Section B.3 in Appendix B of this report). NOTE: Statistical tests for the YRBS were conducted using the “Youth Online” tool (see https://www.cdc.gov/HealthyYouth/yrbs/). Results of testing for statistical significance in this table may differ from published YRBS reports of change. ^a Difference between estimate and 2011 estimate is statistically significant at the .05 level. ^b Difference between estimate and 2011 estimate is statistically significant at the .01 level. Sources: Centers for Disease Control and Prevention, Youth Risk Behavior Survey, 2005, 2007, 2009, and 2011. SAMHSA, Center for Behavioral Health Statistics and Quality, National Survey on Drug Use and Health, January-June for 2005, 2007, 2009, and 2011.
Marijuana
Lifetime Use	38.4	38.1	36.8^a	39.9	28.1	26.4^b	27.8	29.3
Past Month Use	20.2^a	19.7^b	20.8^a	23.1	11.2^b	10.9^b	12.0	13.3
Cocaine
Lifetime Use	7.6	7.2	6.4	6.8	3.8^b	3.8^b	2.9	2.3
Past Month Use	3.4	3.3	2.8	3.0	0.8	0.6	0.4	0.5
Ecstasy
Lifetime Use	6.3^b	5.8^b	6.7^a	8.2	2.8^b	2.9^b	3.3^b	4.3
Past Month Use	—	—	—	—	0.4^a	0.4^a	0.8	0.7
Inhalants
Lifetime Use	12.4	13.3^b	11.7	11.4	12.0^b	10.7^b	10.1^b	8.1
Past Month Use	—	—	—	—	1.1^a	1.1^a	0.6	0.6
Cigarettes
Lifetime Use	54.3^b	50.3^b	46.3	44.7	39.0^b	35.2^b	33.7^a	31.3
Past Month Use	23.0^b	20.0	19.5	18.1	17.0^b	15.5	14.9	14.5
Alcohol
Lifetime Use	74.3	75.0^b	72.5	70.8	57.5^b	57.6^b	56.5^b	52.4
Past Month Use	43.3^b	44.7^b	41.8^b	38.7	26.0^a	26.3^b	25.8^a	23.7

Appendix D: References

American Psychiatric Association. (1987). Diagnostic and statistical manual of mental disorders (DSM-III-R) (3rd rev. ed.). Washington, DC: Author.

American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (DSM-IV) (4th ed.). Washington, DC: Author.

Aquilino, W. S. (1994). Interview mode effects in surveys of drug and alcohol use: A field experiment. Public Opinion Quarterly, 58, 210-240.

Assistant Secretary of Defense for Health Affairs. (2011, August). 2011 Health Related Behaviors Survey to be launched in August:300,000 service members to be asked to participate;1st time on-line [news release]. Washington, DC: Office of the Secretary of Defense.

Bray, R. M., Pemberton, M. R., Hourani, L. L., Witt, M., Rae Olmsted, K. L., Brown, J. M., Weimer, B. J., Lane, M. E., Marsden, M. E., Scheffler, S. A., Vandermaas-Peeler, R., Aspinwall, K. R., Anderson, E. M., Spagnola, K., Close, K. L., Gratton, J. L., Calvin, S. L., & Bradshaw, M. R. (2009, September). 2008 Department of Defense Survey of Health Related Behaviors Among Active Duty Military Personnel: A component of the Defense Lifestyle Assessment Program (DLAP) (RTI/10940-FR, prepared under Contract No. GS-10F-0097L, Task Order No. W81XWH-07-F-0538, for the Assistant Secretary of Defense (Health Affairs) and Task Order No. HSCG23-07-F-PMD047 for the U.S. Coast Guard). Research Triangle Park, NC: RTI International.

Brener, N. D., Eaton, D. K., Kann, L., Grunbaum, J. A., Gross, L. A., Kyle, T. M., & Ross, J. G. (2006). The association of survey setting and mode with self-reported health risk behaviors among high school students. Public Opinion Quarterly, 70, 354-374.

Butler, M. A., & Beale, C. L. (1994, September). Rural–urban continuum codes for metro and non-metro counties, 1993 (Staff Report No. AGES 9425). Washington, DC: U.S. Department of Agriculture, Economic Research Service.

Caetano, R. (2006). NESARC findings on alcohol abuse and dependence. Alcohol Research & Health, 29, 152-155.

Catalano, R. F., Hawkins, J. D., Berglund, M. L., Pollard, J. A., & Arthur, M. W. (2002). Prevention science and positive youth development: Competitive or cooperative frameworks? Journal of Adolescent Health, 31(6 Suppl.), 230-239.

Center for Behavioral Health Statistics and Quality. (2011). Results from the 2010 National Survey on Drug Use and Health: Summary of national findings (HHS Publication No. SMA 11-4658, NSDUH Series H-41). Rockville, MD: Substance Abuse and Mental Health Services Administration.

Center for Behavioral Health Statistics and Quality. (2012). Drug Abuse Warning Network, 2010: Selected tables of national estimates of drug-related emergency department visits. Rockville, MD: Substance Abuse and Mental Health Services Administration.

Chromy, J. R., Feder, M., Gfroerer, J., Hirsch, E., Kennet, J., Morton, K. B., Piper, L., Riggsbee, B. H., Snodgrass, J. A., Virag, T. G., & Yu, F. (2010). Reliability of key measures in the National Survey on Drug Use and Health (HHS Publication No. SMA 09-4425, Methodology Series M-8). Rockville, MD: Substance Abuse and Mental Health Services Administration, Office of Applied Studies.

Cohen, J. (1960). A coefficient of agreement for nominal scales. Educational and Psychological Measurement, 20, 37-46.

Deville, J. C., & Särndal, C. E. (1992). Calibration estimators in survey sampling. Journal of the American Statistical Association, 87, 376-382.

Eaton, D. K., Kann, L., Kinchen, S., Shanklin, S., Flint, K. H., Hawkins, J., Harris, W. A., Lowry, R., McManus, T., Chyen, D., Whittle, L., Lim, C., & Wechsler, H. (2012, June 8). Youth risk behavior surveillance—United States, 2011. Morbidity and Mortality Weekly Report CDC Surveillance Summaries, 61(4), 1-162.

Fendrich, M., Johnson, T. P., Sudman, S., Wislar, J. S., & Spiehler, V. (1999). Validity of drug use reporting in a high-risk community sample: A comparison of cocaine and heroin survey reports with hair tests. American Journal of Epidemiology, 149, 955-962.

Folsom, R. E., & Singh, A. C. (2000). The generalized exponential model for sampling weight calibration for extreme values, nonresponse, and poststratification. In Proceedings of the 2000 Joint Statistical Meetings, American Statistical Association, Survey Research Methods Section, Indianapolis, IN (pp. 598-603). Alexandria, VA: American Statistical Association.

Fryar, C. D., Merino, M. C., Hirsch, R., & Porter, K. S. (2009, May 20). Smoking, alcohol use, and illicit drug use reported by adolescents aged 12-17 years: United States, 1999-2004. National Health Statistics Reports, No. 15, 1-23.

Gfroerer, J., Eyerman, J., & Chromy, J. (Eds.). (2002). Redesigning an ongoing national household survey: Methodological issues (HHS Publication No. SMA 03-3768). Rockville, MD: Substance Abuse and Mental Health Services Administration, Office of Applied Studies.

Gfroerer, J., Hughes, A., Chromy, J., Heller, D., & Packer, L. (2004, July). Estimating trends in substance use based on reports of prior use in a cross-sectional survey. In S. B. Cohen & J. M. Lepkowski (Eds.), Eighth Conference on Health Survey Research Methods: Conference proceedings [Peachtree City, GA] (HHS Publication No. PHS 04-1013, pp. 29-34). Hyattsville, MD: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Center for Health Statistics.

Gfroerer, J., Lessler, J., & Parsley, T. (1997a). Studies of nonresponse and measurement error in the National Household Survey on Drug Abuse. In L. Harrison & A. Hughes (Eds.), The validity of self-reported drug use: Improving the accuracy of survey estimates (NIH Publication No. 97-4147, NIDA Research Monograph 167, pp. 273-295). Rockville, MD: National Institute on Drug Abuse.

Gfroerer, J., Wright, D., & Kopstein, A. (1997b). Prevalence of youth substance use: The impact of methodological differences between two national surveys. Drug and Alcohol Dependence, 47, 19-30.

Grant, B. F., & Dawson, D. A. (2006). Introduction to the National Epidemiologic Survey on Alcohol and Related Conditions. Alcohol Research & Health, 29, 74-78.

Grucza, R. A., Abbacchi, A. M., Przybeck, T. R., & Gfroerer, J. C. (2007). Discrepancies in estimates of prevalence and correlates of substance use and disorders between two national surveys. Addiction, 102, 623-629.

Grunbaum, J. A., Kann, L., Kinchen, S. A., Williams, B., Ross, J. G., Lowry, R., & Kolbe, L. (2002, June 28). Youth risk behavior surveillance—United States, 2001. Morbidity and Mortality Weekly Report CDC Surveillance Summaries, 51(4), 1-62.

Han, B., Gfroerer, J., & Colliver, J. (2009, August). An examination of trends in illicit drug use among adults aged 50 to 59 in the United States: An OAS Data Review. Rockville, MD: U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies.

Harrison, L., & Hughes, A. (Eds.). (1997). The validity of self-reported drug use: Improving the accuracy of survey estimates (NIH Publication No. 97-4147, NIDA Research Monograph 167). Rockville, MD: National Institute on Drug Abuse.

Harrison, L. D., Martin, S. S., Enev, T., & Harrington, D. (2007). Comparing drug testing and self-report of drug use among youths and young adults in the general population (HHS Publication No. SMA 07-4249, Methodology Series M-7). Rockville, MD: Substance Abuse and Mental Health Services Administration, Office of Applied Studies.

Hawkins, J. D., Catalano, R. F., & Miller, J. Y. (1992). Risk and protective factors for alcohol and other drug problems in adolescence and early adulthood: Implications for substance abuse prevention. Psychological Bulletin, 112(1), 64-105.

Hennessy, K. H., & Ginsberg, C. (Eds.). (2001). Substance use survey data collection methodologies and selected papers [Special issue]. Journal of Drug Issues, 31(3), 595-808.

Hughes, A., Muhuri, P., Sathe, N., & Spagnola, K. (2012). State estimates of substance use and mental disorders from the 2009-2010 National Surveys on Drug Use and Health (HHS Publication No. SMA 12-4703, NSDUH Series H-43). Rockville, MD: Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality.

Johnston, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E. (2011). Monitoring the Future national survey results on drug use, 1975-2010: Volume II, College students and adults ages 19-50. Ann Arbor, MI: University of Michigan, Institute for Social Research.

Johnston, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E. (2012). Monitoring the Future national survey results on drug use, 1975-2011: Volume I, Secondary school students. Ann Arbor: University of Michigan, Institute for Social Research.

Kessler, R. C., Avenevoli, S., Costello, J., Green, J. G., Gruber, M. J., Heeringa, S., Merikangas, K. R., Pennell, B. E., Sampson, N. A., & Zaslavsky, A. M. (2009). Design and field procedures in the US National Comorbidity Survey Replication Adolescent Supplement (NCS-A). International Journal of Methods in Psychiatric Research, 18(2), 69-83.

Kessler, R. C., Berglund, P., Chiu, W. T., Demler, O., Heeringa, S., Hiripi, E., Jin, R., Pennell, B. E., Walters, E. E., Zaslavsky, A, & Zheng, H. (2004). The US National Comorbidity Survey Replication (NCS-R): Design and field procedures. International Journal of Methods in Psychiatric Research, 13(2), 69-92.

Kessler, R. C., Chiu, W. T., Demler, O., Merikangas, K. R., & Walters, E. E. (2005). Prevalence, severity, and comorbidity of 12-month DSM-IV disorders in the National Comorbidity Survey Replication. Archives of General Psychiatry, 62, 617-627.

Landis, J. R., & Koch, G. G. (1977). The measurement of observer agreement for categorical data. Biometrics, 33, 159-174.

Manly, B. F. J. (1986). Multivariate statistical methods: A primer. London, England: Chapman and Hall.

Miller, J. W., Gfroerer, J. C., Brewer, R. D., Naimi, T. S., Mokdad, A., & Giles, W. H. (2004). Prevalence of adult binge drinking: A comparison of two national surveys. American Journal of Preventive Medicine, 27, 197-204.

Morton, K. B., Martin, P. C., Shook-Sa, B. E., Chromy, J. R., & Hirsch, E. L. (2012, January 31). Sample design report. In 2011 National Survey on Drug Use and Health: Methodological resource book (Section 2, prepared for the Substance Abuse and Mental Health Services Administration, under Contract No. HHSS283200800004C, Phase II, Deliverable No. 8, RTI/0211838.203.004). Research Triangle Park, NC: RTI International.

Mumola, C. J., & Karberg, J. C. (2006, October [revised January 19, 2007]). Drug use and dependence, State and Federal prisoners, 2004 (NCJ 213530, BJS Special Report). Washington, DC: U.S. Department of Justice, Office of Justice Programs, Bureau of Justice Statistics.

National Center for Health Statistics, Division of Health Interview Statistics. (2011, June). 2010 National Health Interview Survey (NHIS) public use data release: NHIS survey description. Hyattsville, MD: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention.

Office of Applied Studies. (2005). Results from the 2004 National Survey on Drug Use and Health: National findings (HHS Publication No. SMA 05-4062, NSDUH Series H-28). Rockville, MD: Substance Abuse and Mental Health Services Administration.

Office of Applied Studies. (2009). Results from the 2008 National Survey on Drug Use and Health: National findings (HHS Publication No. SMA 09-4434, NSDUH Series H-36). Rockville, MD: Substance Abuse and Mental Health Services Administration.

Office of Management and Budget. (1997). Revisions to the standards for the classification of federal data on race and ethnicity. Federal Register, 62(210), 58781-58790.

Office of Management and Budget. (2003, June 6). OMB Bulletin No. 03-04: Revised definitions of metropolitan statistical areas, new definitions of micropolitan statistical areas and combined statistical areas, and guidance on uses of the statistical definitions of these areas. Washington, DC: The White House.

Partnership at Drugfree.org & MetLife Foundation. (2012, May 2). The Partnership Attitude Tracking Study: 2011 parents and teens full report. New York, NY: Author.

Robertson, E. B., David, S. L., & Rao, S. A. (2003, October). Preventing drug use among children and adolescents: A research-based guide for parents, educators, and community leaders (NIH Publication No. 04-4212(A), 2nd ed.). Bethesda, MD: National Institute on Drug Abuse.

RTI International. (2008). SUDAAN^®, Release 10.0 [computer software]. Research Triangle Park, NC: Author.

RTI International. (2012). 2010 National Survey on Drug Use and Health: Methodological resource book (prepared for the Substance Abuse and Mental Health Services Administration, Office of Applied Studies, under Contract No. HHSS283200800004C, Deliverable No. 39). Research Triangle Park, NC: Author.

Rubin, D. B. (1986). Statistical matching using file concatenation with adjusted weights and multiple imputations. Journal of Business and Economic Statistics, 4(1), 87-94.

Singh, A., Grau, E., & Folsom, R., Jr. (2002). Predictive mean neighborhood imputation for NHSDA substance use data. In J. Gfroerer, J. Eyerman, & J. Chromy (Eds.), Redesigning an ongoing national household survey: Methodological issues (HHS Publication No. SMA 03-3768, pp. 111-133). Rockville, MD: Substance Abuse and Mental Health Services Administration, Office of Applied Studies.

SRNT Subcommittee on Biochemical Verification. (2002). Biochemical verification of tobacco use and cessation. Nicotine & Tobacco Research, 4, 149-159.

Stillwell, R., Sable, J., & Plotts, C. (2011, May). Public school graduates and dropouts from the Common Core of Data: School year 2008–09 (NCES 2011-312, First Look). Washington, DC: U.S. Department of Education, National Center for Education Statistics.

Stinson, F. S., Yi, H.-Y., Grant, B. F., Chou, P., Dawson, D. A., & Pickering, R. (1998, November). Drinking in the United States: Main findings from the 1992 National Longitudinal Alcohol Epidemiologic Survey (NLAES) (NIH Publication No. 99-3519, U.S. Alcohol Epidemiologic Data Reference Manual, Vol. 6, 1st ed.). Bethesda, MD: National Institutes of Health, National Institute on Alcohol Abuse and Alcoholism.

Tourangeau, R., & Smith, T. W. (1996). Asking sensitive questions: The impact of data collection mode, question format, and question context. Public Opinion Quarterly, 60, 275-304.

Turner, C. F., Lessler, J. T., & Gfroerer, J. C. (Eds.). (1992). Survey measurement of drug use: Methodological studies (HHS Publication No. ADM 92-1929). Rockville, MD: National Institute on Drug Abuse.

Appendix E: List of Contributors

This National Survey on Drug Use and Health (NSDUH) report was prepared by the Center for Behavioral Health Statistics and Quality (CBHSQ), Substance Abuse and Mental Health Services Administration (SAMHSA), U.S. Department of Health and Human Services (HHS), and by RTI International (a trade name of Research Triangle Institute), Research Triangle Park, North Carolina. Work by RTI was performed under Contract No. HHSS283200800004C.

Contributors at SAMHSA listed alphabetically, with chapter authorship noted, include Peggy Barker, Jonaki Bose (Chapter 1), Joseph Gfroerer (Chapter 8), Beth Han (Chapter 7), Sarra L. Hedden, Michael Jones (Chapter 4), Joel Kennet (Chapter 3), Rachel Lipari (Chapter 6), Pradip Muhuri (Chapter 5), Dicy Painter, and Peter Tice (Project Officer) (Chapter 2).

Contributors and reviewers at RTI listed alphabetically include Jeremy Aldworth, Heather Archambault, Kat Asman, Stephanie Barnett, Ellen Bishop, Pinliang (Patrick) Chen, James R. Chromy, Jennifer Cooney, Elizabeth Copello, G. Lance Couzens, Devon S. Cribb, Christine Davies, Teresa R. Davis, Ralph E. Folsom, Jr., Misty S. Foster, Peter Frechtel, Julia Gable, Rebecca A. Granger, Wafa Handley, Erica Hirsch, David Cunningham Hunter, Ilona Johnson, Greta Kilmer, Phillip Kott, Larry A. Kroutil, Dan Liao, Peilan Chen Martin, Martin Meyer, Andrew Moore, Katherine B. Morton, N. Ben Neely, Scott Novak, Lisa E. Packer, Michael R. Pemberton, Jeremy Porter, Harley Rohloff, Neeraja S. Sathe, Victoria Scott, Kathryn Spagnola, Thomas G. Virag (Project Director), Jiantong (Jean) Wang, and Lauren Klein Warren.

Also at RTI, report and Web production staff listed alphabetically include Teresa F. Bass, Debbie F. Bond, Kimberly Cone, Valerie Garner, Anne Gering, E. Andrew Jessup, Tayo Jolaoso, Shari B. Lambert, Farrah Bullock Mann, Brenda K. Porter, Pamela Couch Prevatt, Roxanne Snaauw, Marissa R. Straw, Richard S. Straw, Pamela Tuck, and Cheryl Velez.

End Notes

¹ RTI International is a trade name of Research Triangle Institute.
² For example, 2010 MTF data indicated a leveling or possible increase in current cigarette use among youths, in contrast to the 2010 NSDUH data, which showed a continuing decline. The 2011 MTF estimate, however, was lower than the 2010 estimate, and over the long term, the two surveys showed consistent trends. From 2006 to 2011, NSDUH and MTF each showed a 2.6 percentage point decline in youth cigarette use (Figure 8.2).
³ Prior to 2002, the survey was known as the National Household Survey on Drug Abuse (NHSDA).
⁴ One large sample State, Pennsylvania, had a lower final sample size (3,074) because of interviews that were dropped due to data quality issues. Florida received a portion of the GCO supplement and therefore had a higher sample size (4,029).
⁵ The State at the top end of the range (Louisiana, with a sample size of 1,746) included a portion of the GCO supplement.
⁶ SAE is a hierarchical Bayes modeling technique used to make State-level estimates for 25 measures related to substance use and mental health. For more details, see the State Estimates of Substance Use and Mental Disorders from the 2009-2010 National Surveys on Drug Use and Health (Hughes, Muhuri, Sathe, & Spagnola, 2012).
⁷ Sampling areas were defined using 2000 census geography. Counts of dwelling units (DUs) and population totals were obtained from the 2000 decennial census data supplemented with revised population counts from Nielsen Claritas.
⁸ Census tracts are relatively permanent statistical subdivisions of counties and parishes and provide a stable set of geographic units across decennial census periods.
⁹ Some census tracts had to be aggregated in order to meet the minimum DU requirement of 150 DUs in urban areas and 100 DUs in rural areas.
¹⁰ The sample was selected from up to four segments per calendar quarter in SSRs receiving the GCO supplement.
¹¹ A successfully screened household is one in which all screening questionnaire items were answered by an adult resident of the household and either zero, one, or two household members were selected for the NSDUH interview.
¹² The usable case rule requires that a respondent answer “yes” or “no” to the question on lifetime use of cigarettes and “yes” or “no” to at least nine additional lifetime use questions.
¹³ Prior to 2002, NSDUH was known as the National Household Survey on Drug Abuse (NHSDA).
¹⁴ Substances include alcohol, marijuana, cocaine, heroin, hallucinogens, inhalants, pain relievers, tranquilizers, stimulants, and sedatives.
¹⁵ See Section B.4.8 in the Results from the 2008 National Survey on Drug Use and Health: National Findings (OAS, 2009) for the methamphetamine analysis decisions.
¹⁶ For details on how the Census Bureau creates the postcensal estimates, see https://www.census.gov/popest/methodology/2011-nat-st-co-meth.pdf.
¹⁷ Unlike racial/ethnic groups discussed elsewhere in this report, race domains in this section include Hispanics in addition to persons who were not Hispanic.
¹⁸ Additional tables for perceived risk associated with substance use, need for and receipt of treatment, and driving under the influence of alcohol or other drugs also are available at https://www.samhsa.gov/data/NSDUH/NSDUHCensusEffects/Index.aspx, but they are not discussed in this section.
¹⁹ Some 2010 (Old) estimates may differ from previously published estimates due to updates (see Section B.3).
²⁰ See Tables 1.5A, 1.7A, 1.8A, and 1.11A at https://www.samhsa.gov/data/NSDUH/NSDUHCensusEffects/Index.aspx.
²¹ See Tables 1.2A and 1.7A at https://www.samhsa.gov/data/NSDUH/NSDUHCensusEffects/Index.aspx.
²² See Tables 1.2A and 1.7A at https://www.samhsa.gov/data/NSDUH/NSDUHCensusEffects/Index.aspx.
²³ See Tables 1.2B and 1.7B at https://www.samhsa.gov/data/NSDUH/NSDUHCensusEffects/Index.aspx.
²⁴ See Tables 1.11B, 1.12B, and 1.13B at https://www.samhsa.gov/data/NSDUH/NSDUHCensusEffects/Index.aspx.
²⁵ See Tables 1.3B, 1.7B, and 1.8B at https://www.samhsa.gov/data/NSDUH/NSDUHCensusEffects/Index.aspx.
²⁶ See Tables 1.4B, 1.7B, and 1.8B at https://www.samhsa.gov/data/NSDUH/NSDUHCensusEffects/Index.aspx.
²⁷ See Tables 1.14B, 1.15B, and 1.16B at https://www.samhsa.gov/data/NSDUH/NSDUHCensusEffects/Index.aspx.
²⁸ See Tables 1.17A, 1.18A, and 1.19A at https://www.samhsa.gov/data/NSDUH/NSDUHCensusEffects/Index.aspx.
²⁹ See Tables 1.20A, 1.21A, and 1.22A at https://www.samhsa.gov/data/NSDUH/NSDUHCensusEffects/Index.aspx.
³⁰ To examine estimates that are comparable with MTF data, NSDUH estimates presented in Table C.1 are based on data collected in the first 6 months of the survey year and are subset to ages 12 to 20.
³¹ To examine estimates that are comparable with YRBS data, NSDUH estimates presented in Table C.2 are based on data collected in the first 6 months of the survey year and are subset to ages 12 to 20.