An overview of the National Asthma Survey (NAS)

1. An overview of the National Asthma Survey (NAS) Kathleen S. O’Connor, MPH National Center for Health Statistics Division of Health Interview Statistics Special Populations Survey Branch State and Local Area Integrated Telephone Survey (SLAITS) July 13, 2004

2. Objectives • Examine the health, socioeconomic, behavioral, and environmental predictors that relate to better control of asthma • Characterize the content of care and health care experiences of persons with asthma • Provide detailed information about asthma treatment and control

3. Background and unique features • Sponsored by National Center for Environmental Health (CDC) • Complements and extends survey work from other large Federal survey and surveillance systems such as the NHIS, NHANES, and the BRFSS: • Adds depth to the existing body of asthma data • Helps address critical questions surrounding the health, physical environment, and experiences of persons with asthma • Assists researchers in understanding factors that relate to better control of asthma

4. Unique features • Comprehensive snapshot • Includes BRFSS asthma variables for direct comparison • Indicators are consistent across the samples (same instrument) • Adults and children

5. Methodology • Random-Digit-Dial (RDD) telephone survey • National Immunization Survey (NIS) sampling frame • 20 – 25 minutes in length excluding the NIS interview (NAS after the NIS) • Also had a NAS-only component that did not receive the NIS

6. Methodology • Multiple samples: • National • Four states (AL, CA, IL, TX) • Fielded February 27, 2003 – February 20, 2004 (national) • Fielded March 1, 2003 – March 10, 2004 (states) • Adjusted weights (non-response bias, non-coverage of non-telephone households)

7. NAS interview process • National: • All HH members eligible • One person (adult or child) randomly selected per HH regardless of asthma status • Collected detailed information on asthma status, history, knowledge, management, and home environment for persons with asthma • Collected insurance, home environment, and family history for persons with and without asthma • Four States (AL, CA, IL, TX): • Screened all household members for asthma • In asthma + HH—max one child and one adult per HH were randomly selected for detailed questionnaire (child MKP report, adult self report)

9. A brief stroll through the questionnaire: select indicators by survey domain

10. Asthma Introduction • Lifetime and current asthma status • Age and gender of selected person • Respondent relationship

11. Detailed asthma screening • Age at diagnosis • Length of time since last discussion with doctor about asthma • Length of time since taking asthma meds • Length of time since experiencing asthma symptoms

12. History of asthma • Any symptoms past 30 days • Continuity of symptoms throughout day • Difficult sleep due to asthma—past 30 days • Past 2 weeks—how many days symptom free • Past 12 months--asthma episodes • Past 3 months—number of asthma attacks • Length of most recent attack • Relative length of most recent attack

13. Health care utilization Most Qs = past 12 months • Insurance coverage • Doctor visit for asthma • ER/urgent care visits • Urgent doctor visits due to worsening symptoms • Overnight stays in hospital • After last hospital stay did HCP talk about how to better control asthma to prevent episodes or hospitalization • Unable to work or carry out usual activities • Missed school days • Limited usual activities

14. Knowledge of asthma • MD or HCP ever taught: • Recognition of early signs/symptoms of attack • What to do during attack • How to use a peak flow meter • Presence/absence of asthma management plan • Taken course on how to manage asthma

15. Modifications to the environment • Use of: air cleaner, purifier, dehumidifier, exhaust fan in kitchen, gas stove • Mold inside home • Indoor pets • Cockroaches in home • Fireplace or wood burning stove • Unvented gas logs, fireplace, or stove • Smoking inside home

16. Environment …… continued • Has HCP ever advised R to change things inside home, school, or work to improve asthma • Use of mattress cover or pillow to control dust mites • Carpeting or rugs in bedroom • Temperature of wash water for sheets and pillowcases • Exhaust fan in bathroom • Pet allowed in bedroom? • Cigarette smoking, frequency • Current employment status • Job exposure to chemicals, smoke, fumes or dust

17. Medications • OTC meds • Ever used prescription inhaler • HCP taught how to use inhaler • Names, amount, and how often for each med (pill or syrup, inhaler, Nebulizer) • Spacer use

18. Family history of asthma • Anyone else in HH w/asthma • # biological siblings • Asthma in biological parents, brothers, sisters, grandparents; if so, whom

19. Demographics • Race, ethnicity • Education • Height, weight for BMI calculation • Birth weight of selected child • Income

20. Timeline • Data cleaning, review, weighting: Summer 2004 • Public Use data files will be released as soon as they have been prepared and the necessary reviews and approvals have been obtained, including review by the NCHS Disclosure Review Board • Public Use File release: Anticipated Late 2004 or Early 2005

21. For more information: • www.cdc.gov/nchs/slaits.htm • SLAITS listserve (directions on website) • slaits@cdc.gov • 301 - 458 - 4181 Thank you for your interest!