• 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
  • MCQ010 - Ever been told you have asthma
  • MCQ025 - Age when first had asthma
  • MCQ035 - Still have asthma
  • MCQ040 - Had asthma attack in past year
  • MCQ050 - Emergency care visit for asthma/past yr
  • AGQ030 - Did SP have episode of hay fever/past yr
  • MCQ053 - Taking treatment for anemia/past 3 mos
  • MCQ080 - Doctor ever said you were overweight
  • MCQ092 - Ever receive blood transfusion
  • MCD093 - Year receive blood transfusion
  • MCQ145 - CHECK ITEM
  • MCQ149 - Menstrual periods started yet?
  • MCQ151 - Age in years at first menstrual period
  • RHD018 - Estimated age in months at menarche
  • MCQ160a - Doctor ever said you had arthritis
  • MCQ195 - Which type of arthritis was it?
  • MCQ160b - Ever told had congestive heart failure
  • MCD180b - Age when told you had heart failure
  • MCQ160c - Ever told you had coronary heart disease
  • MCD180c - Age when told had coronary heart disease
  • MCQ160d - Ever told you had angina/angina pectoris
  • MCD180d - Age when told you had angina pectoris
  • MCQ160e - Ever told you had heart attack
  • MCD180e - Age when told you had heart attack
  • MCQ160f - Ever told you had a stroke
  • MCD180F - Age when told you had a stroke
  • MCQ160m - Ever told you had thyroid problem
  • MCQ170m - Do you still have thyroid problem
  • MCD180M - Age when told you had thyroid problem
  • MCQ160p - Ever told you had COPD, emphysema, ChB
  • MCQ160l - Ever told you had any liver condition
  • MCQ170l - Do you still have a liver condition
  • MCD180l - Age when told you had a liver condition
  • MCQ500 - Ever told you had any liver condition
  • MCQ510a - Liver condition: Fatty liver
  • MCQ510b - Liver condition: Liver fibrosis
  • MCQ510c - Liver condition: Liver cirrhosis
  • MCQ510d - Liver condition: Viral hepatitis
  • MCQ510e - Liver condition: Autoimmune hepatitis
  • MCQ510f - Liver condition: Other liver disease
  • MCQ515 - CHECK ITEM
  • MCQ520 - Abdominal pain during past 12 months?
  • MCQ530 - Where was the most uncomfortable pain
  • MCQ540 - Ever seen a DR about this pain
  • MCQ550 - Has DR ever said you have gallstones
  • MCQ560 - Ever had gallbladder surgery?
  • MCQ570 - Age when 1st had gallbladder surgery?
  • MCQ220 - Ever told you had cancer or malignancy
  • MCQ230a - 1st cancer - what kind was it?
  • MCQ230b - 2nd cancer - what kind was it?
  • MCQ230c - 3rd cancer - what kind was it?
  • MCQ230d - More than 3 kinds of cancer
  • MCQ300b - Close relative had asthma?
  • MCQ300c - Close relative had diabetes?
  • MCQ300a - Close relative had heart attack?
  • MCQ366a - Doctor told you to control/lose weight
  • MCQ366b - Doctor told you to exercise
  • MCQ366c - Doctor told you to reduce salt in diet
  • MCQ366d - Doctor told you to reduce fat/calories
  • MCQ371a - Are you now controlling or losing weight
  • MCQ371b - Are you now increasing exercise
  • MCQ371c - Are you now reducing salt in diet
  • MCQ371d - Are you now reducing fat in diet
  • OSQ230 - Any metal objects inside your body?

National Health and Nutrition Examination Survey

2017-March 2020 Data Documentation, Codebook, and Frequencies

Medical Conditions (P_MCQ)

Data File: P_MCQ.xpt

First Published: August 2021

Last Revised: NA

Component Description

The NHANES program suspended field operations in March 2020 due to the coronavirus disease 2019 (COVID-19) pandemic. As a result, data collection for the NHANES 2019-2020 cycle was not completed and the collected data are not nationally representative. Therefore, data collected from 2019 to March 2020 were combined with data from the NHANES 2017-2018 cycle to form a nationally representative sample of NHANES 2017-March 2020 pre-pandemic data. These data are available to the public. Please refer to the Analytic Notes section for more details on the use of the data.

The medical conditions (variable name prefix MCQ) section provides self- and proxy-reported personal interview data on a broad range of health conditions and medical history for both children and adults. The NHANES MCQ section is generally modeled on the “Medical Conditions” questionnaire section of the U.S. National Health Interview Survey.

Eligible Sample

All participants, 1 year and older, in the NHANES 2017-March 2020 pre-pandemic sample are included in this dataset.

Interview Setting and Mode of Administration

The questionnaire was asked, in the home, by trained interviewers using Computer-Assisted Personal Interview (CAPI) system. A proxy provided information for survey participants who were under 16 years of age and for individuals who could not answer the questions themselves. The respondent selected the language of interview (English or Spanish) or requested that an interpreter be used. Hand cards, showing response choices or information that survey participants needed to answer the questions, were used for some questions. The hand cards were printed in English, Spanish, Mandarin Chinese (both traditional and simplified), Korean, and Vietnamese. The interviewer directed the respondent to the appropriate hand card during the interview. When necessary, the interviewer further assisted the respondent by reading the response choices listed on the hand cards.

The NHANES 2017-2018 and 2019-2020 questionnaires are available on the NHANES website.

Quality Assurance & Quality Control

The CAPI system is 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.

After collection, interview data were reviewed by the NHANES field office staff for accuracy and completeness of selected items. The interviewers were required to audio-record interviews and the recorded interviews were reviewed by NCHS staff and interviewer supervisors.

Data Processing and Editing

Frequency counts were checked, “skip” patterns were verified, and the reasonableness of question responses was reviewed. Edits were made to some variables to ensure the completeness, consistency, and analytic usefulness of the data. Edits were also made, when necessary, to address data disclosure concerns.

For the 2019-20 survey cycle, the questions MCQ160G (“Has a doctor or other health professional ever told you that you had emphysema?”), MCQ160K (“Has a doctor or other health professional ever told you that you had chronic bronchitis?”) and MCQ160O (“Has a doctor or other health professional ever told you that you had COPD?”) were replaced by MCQ160P (“Have you ever been told by a doctor or other health professional that you had chronic obstructive pulmonary disease or COPD, emphysema, or chronic bronchitis?”). To make 2017-18 data compatible to 2019-20 data, respondents who responded “Yes” to either MCQ160G, MCQ160K, or MCQ160O were coded as “Yes” to MCQ160P. Respondents who responded “No” to MCQ160G, MCQ160K, and MCQ160O were coded as “No” to MCQ160P.

Analytic Notes

The COVID-19 pandemic required suspension of NHANES 2019-2020 field operations in March 2020 after data were collected in 18 of the 30 survey locations in the 2019-2020 sample. Because the collected data were not nationally representative, these data were combined with data from the previous cycle (2017-2018) to create a 2017-March 2020 pre-pandemic data file. A special weighting process was applied to the 2017-March 2020 pre-pandemic data file. The resulting sample weights in the demographic data file should be used to calculate estimates from the combined cycles. These sample weights are not appropriate for independent analyses of the 2019-2020 data and will not yield nationally representative results for either the 2017-2018 data alone or the 2019-March 2020 data alone. Please refer to the NHANES website for additional information for the NHANES 2017-March 2020 pre-pandemic data, and for the previous 2017-2018 public use data file with specific weights for that 2-year cycle.

Since the questionnaire was asked during the household interview, the interview sample weights should be used in the analysis. However, if the data is joined with data from the Mobile Exam Center (MEC), the MEC sample weights should be used.

Codebook and Frequencies