• Component Description
• Eligible Sample
• Interview Setting and Mode of Administration
• Quality Assurance & Quality Control
• Data Processing and Editing
• Analytic Notes
• Codebook
  • SEQN - Respondent sequence number
  • SMQ020 - Smoked at least 100 cigarettes in life
  • SMD030 - Age started smoking cigarettes regularly
  • SMQ040 - Do you now smoke cigarettes?
  • SMQ050Q - How long since quit smoking cigarettes
  • SMQ050U - Unit of measure (day/week/month/year)
  • SMD057 - # cigarettes smoked per day when quit
  • SMQ078 - How soon after waking do you smoke
  • SMD641 - # days smoked cigs during past 30 days
  • SMD650 - Avg # cigarettes/day during past 30 days
  • SMD093 - May I please see the pack of cigarettes
  • SMDUPCA - Cig 12-digit Universal Product Code-UPC
  • SMD100BR - Cigarette Brand/sub-brand
  • SMD100FL - Cigarette Filter type
  • SMD100MN - Cigarette Menthol indicator
  • SMD100LN - Cigarette Length
  • SMD100TR - FTC Tar Content
  • SMD100NI - FTC Nicotine Content
  • SMD100CO - FTC Carbon Monoxide Content
  • SMQ621 - Cigarettes smoked in entire life
  • SMD630 - Age first smoked whole cigarette
  • SMQ661 - Brand of cigarettes smoked past 30 days
  • SMQ665A - Marlboro variety
  • SMQ665B - Camel variety
  • SMQ665C - Newport variety
  • SMQ665D - Other brand
  • SMQ670 - Tried to quit smoking
  • SMQ848 - # times stopped smoking cigarettes
  • SMQ852Q - How long were you able to stop smoking
  • SMQ852U - Unit of measure (day/week/month/year)
  • SMQ890 - Ever smoked a cigar even 1 time?
  • SMQ895 - How many days smoked a cigar?
  • SMQ900 - Ever used an e-cigarette?
  • SMQ905 - How many days used an e-cigarette?
  • SMQ910 - Ever used smokeless tobacco?
  • SMQ915 - How many days used smokeless tobacco?
  • SMAQUEX2 - Questionnaire Mode Flag

National Health and Nutrition Examination Survey

2017-2018 Data Documentation, Codebook, and Frequencies

Smoking - Cigarette Use (SMQ_J)

Data File: SMQ_J.xpt

First Published: February 2020

Last Revised: NA

Component Description

The Smoking - Cigarette Use (variable name prefix SMQ) dataset provides a history of cigarette use, age at initiation, past 30-day use, cigarette brand, sub-brand and other related details. Questions on ever use of cigars, smokeless tobacco, and electronic nicotine delivery systems (including e-cigarettes) were new in 2015-16 (18 years and older). 

Eligible Sample

All participants aged 12 years and older were eligible. For participants aged 12-17 years, there were no proxy interviews. Questions are limited for youth aged 12-17 years. Each variable in this documentation provides the target age.

Interview Setting and Mode of Administration

For adults aged 18 years or older, questions were asked, in the home, by trained interviewers using the Computer-Assisted Personal Interview (CAPI) system. For youth aged 12-17 years, the questions were asked at the Mobile Examination Center (MEC) during the MEC Interview using the Audio Computer-Assisted Self-Interview (ACASI) system, in English and Spanish only.

Quality Assurance & Quality Control

The CAPI and ACASI systems are programmed with built-in consistency checks to reduce data entry errors. CAPI also uses online help screens to assist interviewers in defining key terms used in the questionnaire.

Data Processing and Editing

During post-data collection, edits were made to ensure completeness, consistency and analytic usefulness of the data.

Analytic Notes

SMDUPCA: The Universal Product Code (UPC) from the cigarette pack barcode and brand name was matched to an data base of domestic and imported cigarettes (based on Nielsen U.S. tobacco sales) containing UPC, cigarette name, sub-brand, package color, as well as filter, length and menthol designation. The UPC was not matched for 106 packs seen. For a select number of brands, the data base also included mean tar, nicotine and CO levels (SMD100TR, SMD100NI, SMD100CO) obtained from the Federal Trade Commission.

SMD100BR: This variable includes the cigarette brand for persons who showed their cigarette pack at the interview (SMD093=1) and persons who did not have their pack (SMD093=2), but reported a usual brand. The cigarette brand was not identified for 4 respondents; these were coded as “other brand.”

SMQ661: Data collection questions on cigarette brands for youth aged 12-17 years were modified in 2013-2014, and were released as SMQ661. SMQ665A—SMQ665D show product sub-brand names. Data on brand of usual cigarette for youths is very limited.

Analysts are advised to carefully review skip patterns for this question series, and to re-code or create new variables, as needed. If skip patterns are not considered, estimates may be based on a portion rather than on the entire population. For example, to determine current cigarette smoking status (based on self-report only), consider the responses for the preliminary question (SMQ.020) about whether persons have smoked 100 cigarettes in lifetime, as well as responses to the follow-up question on current cigarette use (SMQ.040), which are only asked of persons who said “yes” to SMQ.020. NOTE, persons not asked a question due to a skip pattern in previous responses were coded as missing (“.”).

For clarification on all question changes in this section, analysts also should consult the “variable names across cycles,” listing that appears at the end of the frequency counts in the documentation.

For three data release cycle files (1999-2004), all of the tobacco use data obtained for youth during the MEC ACASI interview was released in the SMQMEC data files, and tobacco use data for adults was released in both the SMQ and SMQMEC data files. Beginning in 2005-2006, the data file release format was altered, combining data collection modes, and dividing the data by topic for all ages between two files: SMQ (cigarette use as reported in the home interview) and SMQRTU (recent tobacco use as reported in the MEC). In addition, in 2013-14, the age range changed by mode; the ACASI in the MEC was used only of youths aged 12-17 years. When combining multiple years of tobacco data, analysts are advised to refer to all tobacco-related codebooks and carefully review the target age for each variable in the relevant data files.

Additional questions on tobacco use and exposure are located in SMQRTU, SMQFAM and SMQSHS data files. Biochemical indicators of tobacco exposure, including serum cotinine, are available in several laboratory data files.

The NHANES full sample 2-Year MEC Exam Weights (WTMEC2YR) should be used to analyze the 2017-2018 SMQ variables in conjunction with the laboratory measurements on tobacco exposure or other examination measurements.

Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for further details on the use of sample weights and other analytic issues.

Codebook and Frequencies