Attachements A, P, W

2015 NSDUH, Supporting Statement
Attachment A – Sample Design

SAMPLE DESIGN
2015 National Survey on Drug Use and Health Sample Design
The Center for Behavioral Health Statistics and Quality (CBHSQ) introduced a new sample
design in 2014 which will be used for the 2015 National Survey on Drug Use and Health
(NSDUH). Similar to previous NSDUHs, the 2015 NSDUH sample design is a stratified, multistage area probability design. The sample design provides for estimates by state in all 50 states
and the District of Columbia (DC). As shown in Table 1, the 2015 survey will have a sample
designed to yield 4,560 completed interviews in California; 3,300 completed interviews each in
Texas, New York, and Florida; 2,400 completed interviews each in Illinois, Pennsylvania, Ohio,
and Michigan; 1,500 completed interviews each in Georgia, North Carolina, New Jersey, and
Virginia; 967 completed interviews in Hawaii; and 960 completed interviews in each of the
remaining 37 states and DC, for a total national target sample size of 67,507. The sample will be
selected from 6,000 area segments which vary in size according to state. For the 2015 NSDUH,
each state sample will be allocated to age groups as follows: 25 percent 12 to 17, 25 percent18 to
25, 15 percent 26 to 34, 20 percent 35 to 49, and 15 percent 50 or older.
Table 1. Sample Sizes and Projected Respondents by State and Age Group, 2015 NSDUH

State

Total
Population
CA
TX, NY, FL
IL, PA, OH,
MI
GA, NC, NJ,
VA
HI
Remaining
37 States and
DC

State
Sampling
Regions
(SSRs)

Segment
Size

No. of
Segments

15.833
13.75

6,000
288
240

Age
12–17

Age
18–25

Age
26–34

Age
35–49

Age
50+

Total
Age
12+

16,877
1,140
825

16,877
1,140
825

10,126
684
495

13,501
912
660

10,126
684
495

67,507
4,560
3,300

750
36
30

600

600

360

480

360

2,400

24

12.5

192

375
242

375
242

225
145

300
193

225
145

1,500
967

15
12

12.5
10.07

120
96

240

240

144

192

144

960

12

10

96

Beginning in 2014 and continuing with the 2015 NSDUH, the sample will be designed to yield a
minimum of 200 completed interviews in Kauai County, Hawaii over a three-year period. This
will allow for Kauai County to be included as a separate entity in the production of substate
estimates that are produced biennially and typically based on three years of data. To achieve this
goal while maintaining precision at the state level, Kauai County will be treated separately from
the remainder of Hawaii for sample allocation and sample size management purposes. The
annual sample in Hawaii will consist of 67 completed interviews in Kauai and 900 completed
interviews in the remainder of the state, for a total of 967 completed interviews each year.

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Finally, the 2015 design includes the selection of Census block groups at the second stage of
selection. This stage of selection was included beginning in 2014 to facilitate moving to an
address-based sample (ABS) design in the future, if desired. Compared to geocoding at the
Census block level, geocoding accuracy improves significantly at the Census block group level
in both rural and urban areas. Thus, in an ABS design, Census block groups would serve as
geographic clusters in areas with sufficient mailing address coverage. The selection of Census
tracts at the first stage of selection and Census block groups at the second stage has the potential
to reduce sampling variance by controlling the distribution of selected areas and reducing the
chance of selecting neighboring and possibly similar areas within tracts and block groups. In
addition, the merging of NSDUH data to external data sources for future analysis purposes is
simplified when sampled areas are contained within tract and block group boundaries to the
extent possible.
First, Second, and Third Stages of Selection: Census Tracts, Census Block Groups and
Segments
A coordinated sample for the period 2014-2017 has been selected down to the area segment
level as a means of coordinating the overlap of sample areas from year to year. The “first level”
of stratification within the coordinated design is states. The larger sample sizes obtained at the
state level along with small area estimation (SAE) techniques or direct estimation techniques will
enable the development of estimates for all states, for several demographic subgroups within
each state (e.g., age group and gender), for some Core Based Statistical Areas (CBSAs), and for
other small areas.
The “second level” of stratification within the coordinated design was defined as contiguous
geographic areas (groups of Census tracts) within each state. Within each state, state sampling
regions (SSRs) are of approximately equal size in terms of the population and allocated state
sample, except in Hawaii where Kauai County is its own SSR and the remainder of the state is
divided into equal-sized regions.
The design of the first stage of selection began with the construction of an area sample frame that
contained one record for each census tract in the United States. If necessary, census tracts were
aggregated until each tract had a minimum number of dwelling units. In California, Texas, New
York, Florida, Illinois, Pennsylvania, Ohio, Michigan, Georgia, North Carolina, New Jersey, and
Virginia, this minimum size requirement was 250 dwelling units in urban areas and 200 dwelling
units in rural areas. The basis for the differing minimum dwelling unit requirement in urban and
rural areas is that it is more difficult to meet the requirement in rural areas, and 200 dwelling
units are sufficient to support one field test and two main study samples. In the remaining states
and DCthe number of completed interviews per sampled area is smaller and, therefore, fewer
dwelling units are needed. In these states, the minimum requirement was 150 dwelling units in
urban areas and 100 dwelling units in rural areas. After primary sampling units (PSUs; one or
more census tracts) were formed, a sample was selected within each SSR with probabilities
proportionate to a composite size measure and with minimum replacement. Additional implicit

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stratification was achieved by sorting the first-stage sampling units by a CBSA/SES
(socioeconomic status) indicator 1 and by percent non-Hispanic white prior to selection.
For the second stage of selection, adjacent Census block groups were aggregated within selected
PSUs as necessary to meet the minimum dwelling unit requirements (150 or 250 dwelling units
in urban areas and 100 or 200 dwelling units in rural areas, according to state). After the
resulting secondary sampling units (SSUs; one or more census block groups) were formed, one
SSU was selected per sampled PSU with probability proportionate to a composite size measure.
For the third stage of sampling for the coordinated sample, each of the selected Census block
groups was partitioned into clusters of dwelling units by aggregating adjacent Census blocks.
Consistent with the terminology used in previous surveys, these geographic clusters of blocks are
referred to as segments. Segments were formed so that they contain the same minimum number
of dwelling units as the PSU (i.e., Census tracts) and SSU (i.e., Census block groups) to which
they belong. That is, area segments contain at least 150 or 250 dwelling units in urban areas and
100 or 200 dwelling units in rural areas according to state. Segments were constructed using
2010 Decennial Census data supplemented with 2013 population projections obtained from
outside sources. A sample dwelling unit in the survey refers to either a housing unit or a group
quarters listing unit such as a dormitory room or a shelter bed.
One segment was selected within each selected Census block group with probability
proportionate to a composite size measure. As mentioned previously, segments were formed so
that they will contain sufficient numbers of dwelling units to support one field test and two
annual survey samples. This allows half of the segments used in any given year’s main sample to
be used again in the following year as a means of improving the precision of measures of annual
change. This also allows for any special supplemental sample or field test that SAMHSA may
wish to conduct within the same segments.
A sample of 8 segments per SSR will be used for the 2015 survey year. These 8 segments will be
randomly assigned to quarters and to two panels within each quarter. The panels used in the 2015
survey will be designated as panels 2 and 3. Panel 2 segments have been used for the 2014
survey and will be used for the second time in the 2015 survey. The panel 3 segments will be
used for the 2015 and 2016 surveys. Dwelling units that were not selected for the 2014 survey
will be eligible for selection in the panel 2 segments in 2015.
Approximately one-fourth of the final sample of respondents will be collected from each
calendar quarter. This design feature will help control the influence of seasonal variation on drug
use prevalence estimates and other important survey outcome measures of interest.
Fourth Stage of Selection: Listed Lines
Before any sample selection within selected segments can proceed, specially trained field
household listers will list all dwelling units and potential dwelling units within each selected area
segment. A dwelling unit is either a housing unit for a single household or one of the eligible
1

Four categories are defined as: (1) CBSA/low SES, (2) CBSA /high SES, (3) Non CBSA /low SES, and
(4) Non-CBSA /high SES.

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noninstitutional group quarters listing units that are part of the defined target population. The
listings will be based primarily on observations of the area segment and may include vacant
dwelling units and units that appear to be dwelling units but may actually be used for
nonresidential purposes. The objective of the listing is to attain as complete a listing of eligible
residential addresses as possible; any false positives for residences will be eliminated during the
household screening process after the sample is selected.
The sampling frame for the fourth stage of sample selection will be the lines of listed dwelling
units and potential dwelling units. After accounting for eligibility, nonresponse, and the fifthstage sample selection procedures, it was determined that roughly 178,122 lines will need to be
selected in order to obtain a sample of 67,507 responding persons distributed by state and agegroup as shown in Table 1.
Fifth Stage of Selection: Persons
After dwelling units are selected within each segment, an interviewer will visit each selected
dwelling unit to obtain a roster of all persons residing in the dwelling unit. This roster
information will be used to select 0, 1, or 2 persons for the survey. Sampling rates will be pre-set
by age group and State. Roster information will be entered directly into the electronic screening
instrument which will automatically implement this fifth stage of selection based on the State
and age group sampling parameters.
One exciting consequence of using an electronic screening instrument in the survey is the ability
to efficiently sample from all possible pairs of respondents within a dwelling unit while
preserving the target sampling rates for individuals within 5 age groups (12 to 17, 18 to 25, 26 to
34, 35 to 49, and 50 or older). Using an adaptation of Brewer’s method for samples of size 2, a
sample of 0, 1, or 2 persons will be selected from each dwelling unit. As a consequence, any two
survey-eligible people within a dwelling unit will have a known chance of being selected, that is,
all survey eligible pairs of people will have some nonzero chance of being selected. This feature
of the design is of interest to survey researchers because for example, it will allow analysts to
examine how the drug use propensity of one individual in a family will relate to the drug use
propensity of another family member residing in the same dwelling unit (e.g., the relationship of
drug use between a parent and child).
As illustrated in Table 2, at the fifth stage of selection, roughly 89,641 people will be selected
from within 125,176 screened and eligible dwelling units. Assuming an 85% screening
completion rate and a 75% interview completion rate, these sample sizes are sufficient to obtain
the desired 67,507 person respondents.

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Table 2. Summary of 2015 Main Study Design

Statistic
State Sampling (SS) Regions
Segments
Selected Lines
Eligible Dwelling Units
Completed Screening Interviews
Selected Persons
Completed Interviews

2013
NSDUH
(Actual)
900
7,200
227,075
190,067
160,325
88,742
67,838

2015
NSDUH
750
6,000
178,122
148,015
125,176
89,641
67,507

2013 Rate
(Actual)

2015 Rate

0.84
0.84
0.55
0.76

0.83
0.85
0.72
0.75

Expected Precision of Survey Estimates
The multistage, stratified 2015 survey design has been designed to achieve acceptable precision
for various person subpopulations of interest. The allocation of persons per state and age group
(12-17, 18-25, 26-34, 35-49, and 50 or older) was also taken as a requirement to support direct
estimation in some large sample states and SAE in the remaining states. Table 3 shows the
projected relative standard errors for selected prevalence measures.

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Table 3. Estimated Prevalences and Relative Standard Errors for Key Measures by
Demographic Domain
Measure

Past Month Alcohol Use
Past Month Alcohol Use
Past Month Alcohol Use
Past Month Alcohol Use
Past Month Alcohol Use
Past Month Alcohol Use
Past Month Binge Alcohol Use
Past Month Binge Alcohol Use
Past Month Marijuana Use
Past Month Marijuana Use
Past Month Marijuana Use
Past Month Marijuana Use
Past Month Marijuana Use
Past Month Marijuana Use
Past Month Marijuana Use
Past Month Cigarette Use
Past Month Cigarette Use
Past Month Pain Reliever Use
Past Month Pain Reliever Use
Past Year Alcohol Disorder
Past Year Illicit Drug Disorder
Substance Use Disorder
Past Year Specialty Substance Use Treatment
Past Year SMI
Past Year MDE

Domain

12+
12-20
50+
API,12+
AIAN, 12+
Pregnant, 12-44
18-25
12+
12+
12-17
18-25
50+
API,12+
AIAN, 12+
Pregnant, 12-44
12-17
12+
18-25
12+
12+
12+
50+
12+
18+
18+

Prevalence

0.5211
0.2433
0.4949
0.3759
0.4170
0.0898
0.3950
0.2295
0.0725
0.0722
0.1875
0.0289
0.0282
0.0942
0.0535
0.0655
0.2212
0.0379
0.0187
0.0681
0.0281
0.0379
0.0096
0.0407
0.0687

Projected
RSE

0.0068
0.0225
0.0126
0.0435
0.0676
0.1552
0.0132
0.0115
0.0207
0.0374
0.0225
0.0724
0.1121
0.1588
0.1328
0.0404
0.0131
0.0520
0.0394
0.0210
0.0287
0.0656
0.0592
0.0306
0.0239

Note: Prevalence estimates and RSEs are based on data from the 2012 NSDUH while the
projected RSEs were determined using 2014-2017 state and age sample allocations in a variance
component model.

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2015 NSDUH, Supporting Statement
Attachment P – Interview Incentive Receipt

Interview Incentive Receipt

U.S. Department of Health and Human Services
and
RTI International
thank you for participating in the 2015 National Survey on Drug Use and Health.
In appreciation of your participation in this important study, you are eligible to receive $30 in cash.
Since maintaining the confidentiality of your information is important to us, your name will not be entered on this
form. However, the interviewer must sign and date this form to certify you received (or declined) the cash incentive.

___________________________________
Interviewer

□

Accepted Cash Incentive

_________
Date

__ __ __ __ __ __ __ __ __ __ - __
Case ID

□

Declined Cash Incentive

If you ever feel that you need to talk to someone about mental health issues, you can call the National Lifeline
Network. Counselors are available to talk at any time of the day or night and they can give you information about
services in your area.
1-800-273-TALK or 1-800-273-8255
1-888-628-9454 (Spanish)
http://suicidepreventionlifeline.org/
If you ever feel that you need to talk to someone about drug use issues, you can call the Substance Abuse and Mental
Health Services Administration’s Treatment Referral Helpline. This is a 24-hour service that will help you locate
treatment options near you.
1-800-662-HELP or 1-800-662-4357
1-800-487-4889 (TDD)
http://findtreatment.samhsa.gov
Disposition: Top copy to Respondent, yellow to Field Supervisor, pink to Field Interviewer.

2015 NSDUH, Supporting Statement
Attachment W – Certificate of Participation

U.S. Department of Health
and Human Services

Certificate of Participation
The U.S. Department of Health and Human Services and RTI International would like to thank

[Participant’s Signature]

for participating in the National Survey on Drug Use and Health
on
_____________________________
[Date of Interview]

Field Interviewer

Ilona S. Johnson,

FI ID #

National Field Director
RTI International
3040 Cornwallis Road
Research Triangle Park, NC 27709

This document certifies that the above named individual participated in NSDUH, a voluntary survey for the U.S. Department of Health and
Human Services. Across the country, some participants approach their school teachers or other group leaders to ask about possible special
community service credit as they completed this important national survey. The time commitment for participation in this survey is between 1
and 2 hours. A copy of the NSDUH brochure, which explains the study in more detail, should accompany this certificate. If you need further
information, contact the National Field Director, Ilona Johnson, at (800) 848-4079.