• 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)
  • SMD055 - Age last smoked cigarettes regularly
  • 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)
  • SMAQUEX2 - Questionnaire Mode Flag
• Appendix: Variable names across cycles

National Health and Nutrition Examination Survey

2013-2014 Data Documentation, Codebook, and Frequencies

Smoking - Cigarette Use (SMQ_H)

Data File: SMQ_H.xpt

First Published: October 2015

Last Revised: September 2016

Note: The cigarette brand and associated variables were added.

Component Description

The smoking - cigarette use (variable name prefix SMQ) data set provides data on history of use, age at initiation, past 30 day use, cigarette brand, sub-brand and other related details. For adults, two new questions on quit attempts have been added in 2013-14. Also cigarette brand name, sub-brand, and other brand descriptors have been updated to reflect U.S. FDA cigarette product naming and packaging requirements.

Eligible Sample

All participants aged 12 years and older were eligible. For participants aged 12-17 years, there were no proxy interviews.

Interview Setting and Mode of Administration

Beginning in 2013-14, the age range changed by collection mode. 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 youths 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. ACASI was the previous data collection mode for youths aged 12-19 years.

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

Edits were made to ensure completeness, consistency and analytic usefulness of the data. Note that because data are self-reported, certain inconsistencies remain. For example, some adult respondents reported smoking “everyday” in SMQ040, but then reported fewer than 30 days when questioned about the number of days smoked during the past 30 days (SMD641). Analysts should review responses to questions carefully prior to analysis.

A special variable, SMAQUEX was created as a flag to designate each interview mode.

Analytic Notes

Please consult “variable names across cycles,” found at the end of this documentation for further clarification of all changes in 2013-14.

SMQ078: “How soon after waking do you smoke” has expanded response categories in this data release. Categories can be collapsed in order to analyze the variable SMQ077 in earlier cycles.

SMDUPCA: The Universal Product Code (UPC) from the cigarette pack barcode and name was matched to an updated Nielsen data base of domestic and imported cigarettes containing UPC, cigarette name, sub-brand, package color, as well as filter, length and menthol designation. 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: The cigarette brand names and sub-brand now reflect the current product naming and packaging. This variable includes the cigarette brand for persons who had 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 for 13 respondents who provided a cigarette pack was not identified.

Data collection questions on cigarette brands for youth aged 12-17 years also were modified in 2013, and are released as SMQ661, SMQ665A—SMQ665D, with new product sub-brand names.

Additional questions on tobacco use and exposure are located in SMQRTU, SMQFAM and SMQSHS data files. Biologic indicators of tobacco exposure, serum cotinine (metabolite of nicotine) and urinary NNAL measurements can be found in the COTNAL laboratory data file. For adults 20 years and older, a special subset of tobacco-related volatile organic compounds found in urine also are available (UVOCS).

Note that for three data release cycles (1999-2004), all of the tobacco use data obtained for youths 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. However, beginning in 2005-2006, the data 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. Therefore, when analysts are combining multiple years of tobacco data it is critical to refer to all tobacco-related codebooks and carefully review the target age for each variable in the relevant data files.

The NHANES full sample 2-Year MEC Exam Weights (WTMEC2YR) should be used to analyze the 2013-14 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