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

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

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

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

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

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)

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)

SampleDescriptionNumber of participants Goal NationalAdults and children 10,054 persons screened 8,621 respondents Prevalence (adults and children) StatesAdults and children with asthma 5,227 households screened 5,741 respondents (potential of >1/HH) No prevalence Focuses on detailed characteristics of persons with asthma

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

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

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

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

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

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

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

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 Environment …… continued

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 Medications

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

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

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

For more information: SLAITS listserve (directions on website) Thank you for your interest!