Community Action Against Asthma (CAAA) is a community-based participatory research program which combines an investigation of environmental triggers of asthma with an intervention designed to reduce exposure to these triggers and improve the health status of children with asthma.  The central research hypotheses are:

1. exposure to outdoor air contaminants will potentiate the adverse effects of common indoor air contaminants on the health status of asthmatic children;
2. an intensive household level intervention will increase behaviors and psychosocial factors associated with improved asthma-related health status, reduce indoor exposures to environmental triggers, and improve asthma-related health status; and
3. the addition of an neighborhood intervention will enhance the positive effects of the household intervention.

Intervention Design
The household intervention consists of a one-year intensive phase followed by another one-year less intensive phase.  Each of the approximately 300 households participating in the project is visited eleven times by a Community Environmental Specialist in the first year and three times in the second year. Activities during visits include:

• formulation of a household-specific environmental plan,
• education on reduction of exposure to asthma triggers,
• provision of materials needed for modification of the home environment, and
• referrals for medical care, tenant issues, and smoking cessation.

A staggered design is used in which one half of the participants receive the household intervention beginning immediately after the collection of baseline data (see below), and the other half receive the intervention beginning one year later.  At the same time that the intervention is initiated for the second group, the neighborhood intervention, which is based on the community organizing model, also begins for both groups.

Data Collection and Evaluation Methods
The CAAA intervention is evaluated through a comprehensive baseline assessment, which is then repeated on an annual basis. This assessment includes:

1. questionnaires for parents and children covering demographics, asthma severity, medication use, asthma health services utilization, quality of life measures, psychosocial factors and potential confounding factors;
2. observational checklists measuring household and neighborhood environmental hazards;
3. standardized household dust sampling for concentrations of cockroach, dust mite, cat, dog, mouse, and rat antigens; and,
4. skin prick testing (performed only at baseline) of participating children for these same antigens plus ragweed, mixed grasses, and Alternaria.

In addition, seasonal data collected to investigate associations between outdoor and indoor exposures and the children's health status (see below) are also used to assess intervention success.

The seasonal data are collected during intensive two-week periods in each of eleven consecutive seasons over 2+ years.  Exposure quantification is based on the following measures collected in each of these time periods (note: PM = particulate matter):

1. information routinely collected on, for example, PM10, PM2.5, and ozone at several stationary sites in Detroit by governmental agencies;
2. outdoor and indoor sampling at 2 school sites for PM2.5 and PM10, continuous PM2.5 using tapered element oscillating microbalance (TEOM) instruments; with analysis for mass, XRF (trace elements), elemental and organic carbon;
3. similar outdoor/indoor sampling at 20 of the participating households including indoor measures of vapor phase nicotine (e.g., tobacco smoke);
4. personal samples on children in the same 20 households for PM10.

Health outcomes are assessed on a daily basis during the same two-week periods in each of the eleven consecutive seasons.  The assessment includes:

1. a diary of symptoms, medications, and activity level; and
2. morning and evening measurement of forced expiratory volume at one second (FEV1) and peak expiratory flow (PEF) using a portable, hand-held, computerized device (Air Watch brand lung function monitor).

ACCOMPLISHMENTS:

Establishment of the CAAA Steering Committee
The most critical element in the success of the project to date has been the establishment at the outset of a dynamic Steering Committee (SC) comprised of representatives from all of the partner organizations:  Butzel Family Center, Community Health and Social Services, Inc. (CHASS), Detroit Hispanic Development Corporation, Detroiters Working for Environmental Justice, Friends of Parkside, Kettering/Butzel Health Initiative, Latino Family Services, United Community Housing Coalition, Warren/Conner Development Coalition, Detroit Health Department, Henry Ford Health System, Michigan Department of Agriculture - Pesticide and Plant Pest Management Division, and the University of Michigan Schools of Public Health and Medicine.  The Detroit Public Schools also are collaborating with the project.  The SC meets on an at least a monthly basis.  The SC, which has, through a process of consensus, been responsible for all major decisions regarding study design as well as numerous more specific decisions concerning, for example, recruitment strategies, wording of instruments, and hiring of personnel.

Identification and Enrollment of Eligible Children and Families into the Study
A screening questionnaire was distributed in the Fall of 1999 to identify children with asthma then ages 6 to 10.  Over 7500 questionnaires were successfully mailed and about 2000 were distributed in elementary schools.  A total of 3342 screening questionnaires were completed and returned in 1999.  Among the returned questionnaires, 1655 (49.7 %) were consistent with probable or known asthma of any severity.  Among these, 387 (11.5 % of the total returned) had probable or known moderate to severe asthma based on National Asthma Education and Prevention Program diagnostic guidelines and another 116 had mild persistent asthma severe enough for eligibility for the study.

Calculated minimum population-based estimates of prevalence for any asthma (18.9 %) and moderate to severe asthma (4.4 %) substantially exceed national averages.  Among those with known or probable moderate to severe asthma, over 30 percent had not been diagnosed by a physician, over one half were not taking daily asthma medication, and approximately one quarter had not taken any physician-prescribed asthma medication in the past 12 months.

Of the 503 initially considered eligible for the study, approximately 30 were excluded because of living or having moved to an address outside of the target area.  Of the remaining approximately 470 eligible children, slightly over 300 have been successfully enrolled into at least one aspect of the study (skin testing, baseline questionnaire, and/or first seasonal intensive data collection).  Most of those not yet enrolled have proved difficult to contact by phone or mail.  Fewer than 20 families have refused participation.

Other important steps accomplished thus far include:

• development and pilot testing of written instruments in both English and Spanish including the screening questionnaire, adult (caregiver) questionnaire, child questionnaire, a household environmental checklist, and a neighborhood environmental checklist;
• elaboration of study protocols for skin test "fairs", training on use of the Airwatch airway monitor and symptom diary, administration of adult and children baseline questionnaires, completion of household and neighborhood environmental checklists, collection of household dust for allergen analysis, and measurement of personal and indoor household PM levels;
• Hiring and training of staff from the community to serve as interviewers, air monitor and diary trainers, environmental checklist administrators, household dust collectors, and community environmental specialists;
• allergen skin testing of 272 children at 17 skin test "fairs";
• completion with more than 200 families of the adult baseline questionnaires, household walk-through, and household dust collection for allergen analysis;
• participation by 205 families in the first two-week intensive seasonal assessment through daily use of airway monitors and diaries, and, in a subset of about 80 households, measurement of vapor phase nicotine;
• installation of two tapered element oscillating microbalance instruments (TEOMs), for continuous measurement of ambient PM, on the rooftops of two Detroit elementary schools;
• development and production of customized indoor air sampling pump units which were used to collect PM levels in each of the two elementary schools and in participant households during the first two-week intensive seasonal assessment.

Based on preliminary analyses, the proportion of children with positive response to skin prick testing for each allergen is shown below:

The substantial proportion of children positive for allergens of outdoor origin (ragweed, grass, and Alternaria) was somewhat unexpected, and may have important implications for the customization of intervention strategies beyond those that were already envisioned for children allergic to roach and dust mite.

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Updated January 02, 2003