National Health and Nutrition Examination Survey

The Respiratory Disease Section (prefix RDQ) provides interview data on respiratory symptoms that may be related to bronchitis or asthma. The symptoms profiled include cough, phlegm production, and wheezing. Data are also collected on trigger factors for these symptoms and on related functional impairments.

Topics

• History Cough and Phlegm Production (RDD030, RDQ040-RDQ060)

12-month period prevalence of:

• Wheezing (RDQ070); Frequency of Wheezing Episodes (RDQ080)
• Sleep Disturbance Due to Wheezing (RDQ090)
• Wheezing With Exercise (RDQ100)
• Number of Doctor, Hospital or Emergency Room Visits for Wheezing (RDQ120)
• Prescription Medication use for Wheezing (RDD134)
• Limitation of Usual Activities Due to Wheezing (RDQ135)
• Number of Days of Work/School Missed Due to Wheezing (RDQ137)
• Dry Nocturnal Cough (RDQ140)

Questions regarding a history of cough and phlegm production were administered to Survey Participants ages 12 years and above, except for RDQ140 (History of Dry Nocturnal Cough), which was administered to Survey Participants of all ages.

Questions regarding a history of wheezing were administered to Survey Participants of all ages, except for RDQ137, which was administered to Survey Participants ages 6–69 years. As in NHANES 1999–2000, the question series RDQ120, RDD134, RDQ135, and RDQ 137 was administered only to Survey Participants with a history of more severe asthma (a history of recent sleep disturbance due to wheezing plus a history of recent exercise associated wheezing).

Household interview

For details on the QA/QC process for this component, please refer to the procedures manual at
https://wwwn.cdc.gov/nchs/nhanes/continuousnhanes/default.aspx?BeginYear=2001.

Data editing (for example “top coding” of continuous variables) is documented in the RDQ Section Codebook.

These data were collected as part of the NHANES Household Questionnaire Interview, and interview weights should be used if only questionnaire data is analyzed. If RDQ data is merged with the MEC examination data, however, then MEC examination sample weights should be used for the analyses.
Current NHANES questionnaire data collection relating to respiratory symptoms is based on prior NHANES surveys as well as validated survey instruments. It is recommended that data analysts be familiar with current practices and issues in the epidemiologic investigation of respiratory disease (1–4).

Related NHANES 2001–2002 Questionnaire Datasets:

• Medical Conditions (MCQ) contains questionnaire data on a history of a previous medical diagnosis of respiratory disease (asthma, chronic bronchitis, emphysema), age at onset of disease, and family history of asthma.
• Physical Functioning (PFQ) contains data on functional physical limitations as well as information on the type of health problems (including respiratory disease) causing the difficulty.
  Cardiovascular Disease (CDQ) contains data for dyspnea (shortness of breath) on exertion for adults ages 40+.
• Smoking (SMQ) contains data on past history of smoking.
• Occupation (OCQ) includes data on current and past occupations, as well as identification of a Survey Participant's exposure to second-hand smoke in their current job (OCQ290G/Q). Also, for Survey Participants whose asthma began as an adult, the type of employment is recorded (OCQ470-480).
• Prescription Medications (RXQ) contains data on all prescription medications currently taken, as well as a specific question on the number of beta-agonist inhalers taken in the previous month (RXQ280).

Changes from the NHANES 1999–2000 RDQ Section:

Data analysts should note that there are several differences between the RDQ Questionnaire Section in NHANES 1999–2000 vs. the NHANES 2001–2002 RDQ Section:

Data on cough symptoms for children and adolescents (RDQ010, RDQ020G/Q) was not collected in 2001–2002.

The question series for cough and phlegm production (RDQ030-RDQ060) was administered to all Survey Participants in 1999-2000, but only to Participants ages 12+ in 2001–2002. Otherwise, for analytical purposes, RDD030 in NHANES 2001–2002 is equivalent to RDQ030 in NHANES 1999–2000.

NHANES 1999–2000 collected data on both non-prescription and prescription medication use for treatment of wheezing (RDQ130, RDQ133). Only data for prescription medication use for wheezing was collected in NHANES 2001-2002 (RDD134).

Please refer to the Analytic Guidelines for further details on the use of sample weights and other analytic issues at https://wwwn.cdc.gov/nchs/data/nhanes/nhanes_general_guidelines_june_04.pdf.