Description
This assignment covers topics associated with causal inference, confounding, comparison of means and chi-square test of independence.
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EPID 5100
Analytic Methods in Public Health
Fall 2023
Quantitative Assignment 3 Submission Template
PART I: CAUSAL INFERENCE AND CONFOUNDING
1. What is causal inference? Why is it so difficult in observational epidemiology?
Causal inference description
Difficulties in establishing causality in observational
epidemiology.
2. Which study designs are best suited for establishing temporality, and why do they offer a stronger
basis for causal inference than other study designs?
Study designs that establish temporality
Why these designs provide stronger basis for
temporality.
3. Outline and explain one of the causal models from this week’s readings. You may choose the Austin
Bradford Hill considerations, Rothman’s causal pies, or the counterfactual model.
Name of chosen causal model.
Counterfactual Model
Description of chosen causal model.
The counterfactual model serves as a causal inference
framework designed to predict the outcome without a
specific program or intervention. Within this model, a
causal factor is deemed essential, and the outcome is
contingent on its presence. To illustrate, in an
experimental context, the counterfactual represents
the potential outcome that could have transpired but
did not materialize.
4. Identify techniques for reducing bias (from confounding, information, and selection) at the design
phase of a study.
Reduce bias due to confounding.
Reduce information bias.
Randomization between study group, stratification
and adjustment
Choose an appropriate study design and follow rules
for data collection by collecting standards records and
data.
Randomization of the control group
Reduce selection bias.
5. Define confounding. Identify a technique for reducing bias from confounding at the analytical (analysis)
phase of a study.
Confounding definition
Reduce bias due to confounding at analytic level.
6. Calculate the crude odds ratio for the primary exposure (cannabis use) and outcome (oxy use).
Crude Odds Ratio
33.556
7. Using the table below, is there evidence of an association between the potential confounder (drug
education) and the primary exposure (cannabis use)? You may use the odds ratio (OR) to measure this
association. If there is an association, are those receiving drug education more or less likely to use
cannabis?
Association between Drug Education and Cannabis Use?
There is a decrease association between a drug
education and cannabis
0.708
Odds Ratio
Are those receiving drug education more or less Those who have received drug education have 29.2%
decrease in their odds of using cannabis.
likely to use cannabis? What percentage?
8. Calculate the odds ratio for the relationship between oxycodone use and drug education within the
“no cannabis” stratum in the table below.
Odds Ratio
9. Is there an independent association between the potential confounder (drug education) and the
outcome (oxycodone use)? Use the odds ratio results from the table above, and remember that an
odds ratio association can be positive (above 1) or negative (from 0 to 1). A “null” (no association)
odds ratio is exactly 1. To determine whether there is an association, we are restricting to only those
youth who did not use cannabis; explain why this is the appropriate subgroup for this calculation.
People who received a drug education are less likely
Association between Drug Education and Oxycodone
with 41.3% compared with people who haven’t
Use? More or less likely? What percentage?
received health education.
Why restrict to youth who did not use cannabis?
10. Based on the information above, do you think drug education is a confounder of the association
between cannabis use and oxycodone use in this study population? Why or why not?
No, it’s not cofounder. The odds ratio is less than 1.
Is drug education a confounder?
Why or why not?
11. Calculate the stratum-specific odds ratios using the table below.
Drug Education Stratum Odds Ratio
39.7
No Drug Education Stratum Odds Ratio
22.62
12. Calculate the combined odds ratio based on your stratified results (Question 11). To get the combined
odds ratio, you may simply average the two stratum-specific odds ratios (in more advanced courses
you would calculate the Mantel-Haenszel Odds Ratio, but you don’t have to do that here).
Combined Odds Ratio
31.16
13. Does the combined odds ratio (from Question 12) differ from the crude odds ratio (Question 6)? By
what percent? Does this indicate that education is a confounder of the cannabis-opioid association?
Why or why not?
Percent difference between Combined and Crud ORs
Education a confounder? Why or why not?
PART II: COMPARISON OF MEANS AND CHI-SQUARE TEST OF INDEPENDENCE
I.
What is the sample size of the dataset provided in ClassQuant3_4?
Sample size of the dataset provided in ClassQuant3_4
II.
Does it appear that respondents who were dependent on cocaine, used more days on average in the last
year?
Null Hypothesis:
Hypotheses
T-test statistic
P-value
Interpretation of T-test/ p-value (i.e. Do individuals
dependent on cocaine report a significantly higher
number of days using cocaine?)
Research Hypothesis:
Paste SPSS Tables for Question II Here
III.
Does it appear that marital status was associated with the mean number of days on average respondents
reported using cocaine in the last year?
Null Hypothesis:
Hypotheses
Research Hypothesis:
F-test statistic
P-value
Interpretation of F-test/ p-value (i.e. Is marital status
significantly associated with the average number of days
respondents report using cocaine?)
Paste SPSS Tables for Question III Here
IV.
Does it appear that dependence on cocaine is associated with dependence on heroin?
Null Hypothesis:
Hypotheses
Research Hypothesis:
Chi-square statistic
P-value
Interpretation of F-test/ p-value (i.e. Is cocaine
dependence significantly associated with dependence
on heroin?)
Relative Risk
Interpretation of Relative Risk (i.e. Are individuals who
are dependent on cocaine more, less, or the same
amount as likely to be dependent on heroin? If more or
less likely to be dependent on heroin, tell us by what
percentage.)
Paste SPSS Tables for Question IV Here
2019 NATIONAL SURVEY ON
DRUG USE AND HEALTH
PUBLIC USE FILE CODEBOOK
Substance Abuse and Mental Health Services Administration
Center for Behavioral Health Statistics and Quality
Rockville, Maryland 20857
October 20, 2020
2019 NATIONAL SURVEY ON
DRUG USE AND HEALTH
PUBLIC USE FILE CODEBOOK
Contract No. HHSS283201700002C
Project No. 0215638
Deliverable 56
For questions about this codebook and data file, please e-mail
[email protected].
Prepared for: Substance Abuse and Mental Health Services Administration,
Rockville, Maryland
Prepared by: RTI International, Research Triangle Park, North Carolina
Data File Name: PUF2019_100920
October 20, 2020
Recommended Citation: Center for Behavioral Health Statistics and Quality.
(2020). 2019 National Survey on Drug Use and Health Public Use File
Codebook, Substance Abuse and Mental Health Services Administration,
Rockville, MD
Table of Contents
Section
Page
Introduction to the 2019 National Survey on Drug Use and Health ……………………………………… i-1
Introduction ……………………………………………………………………………………………………….. i-1
Overview of NSDUH ………………………………………………………………………………………….. i-2
Survey Redesign in 1999 and Improvements in 2002 …………………………………… i-2
Partial Questionnaire Redesign in 2015 ………………………………………………………. i-3
Summary of Information for 2019 ……………………………………………………………… i-3
Questionnaire Changes for the 2019 NSDUH ………………………………………………………… i-5
Additional Historical Changes to NSDUH Variables of Note…………………………………… i-6
Strengths and Limitations of NSDUH …………………………………………………………………… i-7
Survey Methodology …………………………………………………………………………………………… i-8
Stratification and Selection of Primary, Secondary, and Tertiary Sampling Units
(Census Tracts, Census Block Groups, and Area Segments) ………………………………. i-9
Selection of Dwelling Units ……………………………………………………………………………….. i-10
Selection of Individuals …………………………………………………………………………………….. i-11
Sample Design Variables …………………………………………………………………………………… i-12
Data Collection and Response Rates …………………………………………………………………… i-13
Sample Weights ……………………………………………………………………………………………….. i-13
Organization of the Data File ……………………………………………………………………………… i-14
Usable Cases ……………………………………………………………………………………………………. i-16
Logical Editing…………………………………………………………………………………………………. i-18
Editing Procedure for Substance Use Variables Other than Prescription
Drugs ………………………………………………………………………………………………. i-19
Editing Procedure for Prescription Drug Variables …………………………………….. i-20
Standard Code Conventions …………………………………………………………………….. i-21
Statistical Imputation ………………………………………………………………………………………… i-22
Imputation Indicators ……………………………………………………………………………… i-24
Constraints and Consistency ……………………………………………………………………. i-26
Variance Estimation of Estimated Numbers of Individuals ……………………………………. i-26
Statistical Significance of Differences …………………………………………………………………. i-29
Confidentiality of Data ……………………………………………………………………………………… i-31
Public Use File Weight Calibration …………………………………………………………………….. i-32
Public Use File Estimates and Standard Errors …………………………………………………….. i-33
Special Types of Analyses …………………………………………………………………………………. i-35
List of Tables
Table
Page
1.
Demographic Domains for the Public Use File That Should Use the Alternative
Standard Error Estimation Method for Calculating the Standard Errors of the
Estimated Number of Individuals, Totals: 2019 ……………………………………………………. i-28
2.
Past Month Marijuana Prevalence and Standard Error Ratios of the Public Use
File Subsample to the Full Sample, by Seven Domains: 2019 ………………………………… i-34
3.
Past Year Heroin Prevalence and Standard Error Ratios of the Public Use File
Subsample to the Full Sample, by Seven Domains: 2019 ………………………………………. i-34
TABLE OF CONTENTS
TABLE OF CONTENTS
IDENTIFICATION ……………………………………………………………………………………………………………………………………………………………………………….3
SELF-ADMINISTERED SUBSTANCE USE SECTIONS …………………………………………………………………………………………………………………………4
TOBACCO ………………………………………………………………………………………………………………………………………………………………………………..4
ALCOHOL ………………………………………………………………………………………………………………………………………………………………………………17
MARIJUANA …………………………………………………………………………………………………………………………………………………………………………..22
COCAINE ………………………………………………………………………………………………………………………………………………………………………………..26
CRACK ……………………………………………………………………………………………………………………………………………………………………………………29
HEROIN ………………………………………………………………………………………………………………………………………………………………………………….32
HALLUCINOGENS ………………………………………………………………………………………………………………………………………………………………….36
INHALANTS ……………………………………………………………………………………………………………………………………………………………………………51
METHAMPHETAMINE ……………………………………………………………………………………………………………………………………………………………60
PAIN RELIEVERS SCREENER …………………………………………………………………………………………………………………………………………………64
TRANQUILIZERS SCREENER …………………………………………………………………………………………………………………………………………………65
STIMULANTS SCREENER ………………………………………………………………………………………………………………………………………………………66
SEDATIVES SCREENER ………………………………………………………………………………………………………………………………………………………….67
PAIN RELIEVERS ……………………………………………………………………………………………………………………………………………………………………68
TRANQUILIZERS ……………………………………………………………………………………………………………………………………………………………………77
STIMULANTS …………………………………………………………………………………………………………………………………………………………………………83
SEDATIVES …………………………………………………………………………………………………………………………………………………………………………….91
IMPUTED SUBSTANCE USE …………………………………………………………………………………………………………………………………………………………….97
RECENCY OF DRUG USE ……………………………………………………………………………………………………………………………………………………….97
PAST YEAR FREQUENCY OF USE ………………………………………………………………………………………………………………………………………..106
PAST MONTH FREQUENCY OF USE …………………………………………………………………………………………………………………………………….109
AGE/DATE OF FIRST DRUG USE ………………………………………………………………………………………………………………………………………….114
RECODED DRUG USE …………………………………………………………………………………………………………………………………………………………..124
OTHER SELF-ADMINISTERED SECTIONS………………………………………………………………………………………………………………………………………164
SPECIAL DRUGS …………………………………………………………………………………………………………………………………………………………………..164
RECODED SPECIAL DRUGS …………………………………………………………………………………………………………………………………………..177
RISK/AVAILABILITY ……………………………………………………………………………………………………………………………………………………………179
RECODED RISK/AVAILABILITY …………………………………………………………………………………………………………………………………….184
BLUNTS ………………………………………………………………………………………………………………………………………………………………………………..186
SUBSTANCE DEPENDENCE AND ABUSE …………………………………………………………………………………………………………………………….190
IMPUTED SUBSTANCE DEPENDENCE AND ABUSE ………………………………………………………………………………………………………253
RECODED SUBSTANCE DEPENDENCE AND ABUSE ……………………………………………………………………………………………………..262
SPECIAL TOPICS …………………………………………………………………………………………………………………………………………………………………..271
RECODED SPECIAL TOPICS …………………………………………………………………………………………………………………………………………..279
PRIOR SUBSTANCE USE ………………………………………………………………………………………………………………………………………………………281
DRUG TREATMENT ……………………………………………………………………………………………………………………………………………………………..298
RECODED DRUG TREATMENT ………………………………………………………………………………………………………………………………………333
HEALTH………………………………………………………………………………………………………………………………………………………………………………..349
RECODED HEALTH ………………………………………………………………………………………………………………………………………………………..363
ADULT MENTAL HEALTH SERVICE UTILIZATION ……………………………………………………………………………………………………………..364
RECODED ADULT MENTAL HEALTH SERVICE UTILIZATION ……………………………………………………………………………………..381
SOCIAL ENVIRONMENT ………………………………………………………………………………………………………………………………………………………388
YOUTH EXPERIENCES …………………………………………………………………………………………………………………………………………………………390
RECODED YOUTH EXPERIENCES ………………………………………………………………………………………………………………………………….405
MENTAL HEALTH ………………………………………………………………………………………………………………………………………………………………..411
RECODED MENTAL HEALTH…………………………………………………………………………………………………………………………………………419
ADULT DEPRESSION ……………………………………………………………………………………………………………………………………………………………425
RECODED ADULT DEPRESSION …………………………………………………………………………………………………………………………………….443
YOUTH MENTAL HEALTH SERVICE UTILIZATION …………………………………………………………………………………………………………….448
RECODED YOUTH MENTAL HEALTH SERVICE UTILIZATION ……………………………………………………………………………………..472
ADOLESCENT DEPRESSION …………………………………………………………………………………………………………………………………………………492
RECODED ADOLESCENT DEPRESSION …………………………………………………………………………………………………………………………510
CONSUMPTION OF ALCOHOL ……………………………………………………………………………………………………………………………………………..516
RECODED CONSUMPTION OF ALCOHOL………………………………………………………………………………………………………………………527
MARKET INFORMATION FOR MARIJUANA…………………………………………………………………………………………………………………………532
INTERVIEW INFORMATION …………………………………………………………………………………………………………………………………………………………..548
DEMOGRAPHICS ……………………………………………………………………………………………………………………………………………………………………………549
DEMOGRAPHICS ………………………………………………………………………………………………………………………………………………………………….549
IMPUTED DEMOGRAPHICS ……………………………………………………………………………………………………………………………………………554
RECODED DEMOGRAPHICS …………………………………………………………………………………………………………………………………………..555
EDUCATION …………………………………………………………………………………………………………………………………………………………………………557
RECODED EDUCATION ………………………………………………………………………………………………………………………………………………….561
EMPLOYMENT ……………………………………………………………………………………………………………………………………………………………………..562
IMPUTED EMPLOYMENT……………………………………………………………………………………………………………………………………………….568
Codebook Creation Date: 10/9/2020 ……………………………………………….1
TABLE OF CONTENTS
HOUSEHOLD COMPOSITION (ROSTER) ……………………………………………………………………………………………………………………………….569
PROXY INFORMATION…………………………………………………………………………………………………………………………………………………………571
HEALTH INSURANCE …………………………………………………………………………………………………………………………………………………………..572
IMPUTED HEALTH INSURANCE …………………………………………………………………………………………………………………………………….577
RECODED HEALTH INSURANCE……………………………………………………………………………………………………………………………………579
INCOME ………………………………………………………………………………………………………………………………………………………………………………..580
IMPUTED INCOME …………………………………………………………………………………………………………………………………………………………581
RECODED INCOME ………………………………………………………………………………………………………………………………………………………..583
FI DEBRIEFING QUESTIONS …………………………………………………………………………………………………………………………………………………………..584
GEOGRAPHIC …………………………………………………………………………………………………………………………………………………………………………………585
COUNTY ……………………………………………………………………………………………………………………………………………………………………………….585
SEGMENT ……………………………………………………………………………………………………………………………………………………………………………..586
BLOCK ………………………………………………………………………………………………………………………………………………………………………………….587
SAMPLE WEIGHTING AND ESTIMATION VARS ……………………………………………………………………………………………………………………………588
INDEX …………………………………………………………………………………………………………………………………………………………………………………………….589
APPENDIX A
APPENDIX B
APPENDIX C
APPENDIX D
APPENDIX E
APPENDIX F
APPENDIX G
APPENDIX H
Drug Codes for Open-Ended Questions
Consolidated Drug Other Specify Tables
Tobacco Brand Codes for Open-Ended Questions
Recoded Substance Dependence and Abuse Variable Documentation
Recoded Mental Health
Recoded Depression Variable Documentation
Key Mental Health Variables
Sample SUDAAN®, SAS®, and Stata Code and PUF Estimates
Codebook Creation Date: 10/9/2020 ……………………………………………….2
Introduction to the 2019 National Survey on
Drug Use and Health
Introduction
This codebook provides documentation for the 2019 National Survey on Drug Use and
Health (NSDUH) public use data file. 1 Prior to 2002, the survey was called the National
Household Survey on Drug Abuse (NHSDA). NSDUH is sponsored by the Center for Behavioral
Health Statistics and Quality (CBHSQ, formerly the Office of Applied Studies) within the
Substance Abuse and Mental Health Services Administration (SAMHSA) and is conducted by
RTI International, Research Triangle Park, North Carolina. 2
For each variable in the 2019 data file, the codebook provides the variable name,
a description of the variable, value codes and their meanings, and an unweighted univariate
frequency distribution. Most of the variables originated directly as interview items. For a subset
of variables created from more than one variable, the source variables and recoding
specifications are provided. In addition, case identification, sampling, and data collection
variables are included in the file and documented in the codebook. The variable names in this
codebook are the variable names used in the dataset.
To a great extent, variable names indicate the meaning of each variable. As much as
possible, variables are named consistently across surveys when the content of questions was
identical or similar or when the specifications for creating variables were not altered. When a
variable does not have the same name across years, this is an indication that differences may
exist. In such situations, analysts are advised to examine the codebook documentation in detail
before conducting any analysis, particularly those involving the following:
•
analyses performed in prior years that are being replicated in the current year,
•
comparison of data across multiple years, or
•
use of pooled data from multiple years.
Documentation of the reasons for changing a variable’s name can be found in comments
above the specific variables and in corresponding appendix files within the codebook (if
applicable). Typically, variable changes are documented the year they occur and in the following
year if there are comparability issues to consider. However, the most current version of the
documentation may not always describe relevant changes from prior years. Therefore, analysts
who are doing a multiyear trend analysis are especially advised to examine documentation for all
Information on access to NSDUH restricted-use confidential data files is available from the Substance
Abuse and Mental Health Data Archive (SAMHDA) at https://datafiles.samhsa.gov/.
2
RTI International is a trade name of Research Triangle Institute. RTI and the RTI logo are U.S. registered
trademarks of Research Triangle Institute.
1
i-1
years of interest to identify any change over time that may affect the analysis of interest. 3
An analysis of trends is not recommended when using data where the impact of the questionnaire
or methodological changes are confounded with true changes in the phenomenon being
measured. If the change is considered minor and the likely impact on trend data would be
minimal, then comparisons between years may be appropriate.
Analysts also are encouraged to refer to the instrument specifications for the 2019 survey
in conjunction with their review of the codebook. The specifications for the 2019 survey provide
detailed information about the logic governing how respondents were routed through the
questions in the interview and any changes to the instrument relative to the 2018 survey.
The 2019 specifications may be found on the SAMHSA website at https://www.samhsa.gov/data/.
Overview of NSDUH
The 2019 NSDUH is the 39th in a series, the primary purpose of which is to measure the
prevalence and correlates of substance use and mental health issues in the United States. This
survey series provides information about the use of illicit drugs, alcohol, and tobacco among
members of the U.S. civilian, noninstitutionalized population aged 12 or older. The survey also
includes several modules of questions focusing on mental health issues. Surveys have been
conducted periodically since 1971, with the most recent ones in 1979, 1982, 1985, 1988, and
each year from 1990 through 2019. Currently, public use files are available for surveys from
1979 onward.
Survey Redesign in 1999 and Improvements in 2002
In 1999, the survey underwent a major redesign. The method of data collection was
changed from a paper questionnaire administration to a computer-assisted administration.
In addition, the sample design was changed from a strictly national design to a state-based
sampling plan. These important changes have had a major impact on the data produced from the
survey. Because of the differences in methodology and the impact of the new design on data
collection, only limited comparisons can be made between data from the redesigned surveys
(1999
