The Head-off Environmental Asthma in Louisiana (HEAL) Study-Methods and Study Population [Environmental Health Perspectives]
|By Lichtveld, Maureen|
BACKGROUND: In the city of
OBJECTIVES: The Head-off Environmental Asthma in
METHODS: Children (4-12 years old) with moderate-to-severe asthma were recruited from NOLA schools. Over 1 year, they received two clinical evaluations, three home environmental evaluations, and die asthma intervention. Quarterly end points included symptom days, medication use, and unscheduled emergency department or clinic visits. A community advisory group was assembled and informed HEAL at all phases.
RESULTS: Of the children (n « 182) enrolled in HEAX, 67% were African American, and 25% came from households with annual incomes <
CONCLUSIONS: Despite numerous challenges faced by investigators, study staff, and participants, including destroyed infrastructure, disrupted lives, and lost jobs, HEAL was successful in terms of recruitment and retention, die high quality of data collected that will provide insight into asdimaallergen relationships, and the asthma intervention. This success was attributable to using an adaptive approach and refining processes as needed.
Key WORDS: asthma, asthma case management, asdima counselor, environmental intervention, Hurricane Katrina, indoor allergens, mold. Environ Health Perspect 120:1592-1599 (2012). http:// dx.doi.org/10.1289/ehp.1104239 [Online 15 August 2012]
Hurricane Katrina struck the city of
In addition to the environmental devastation, Katrina destroyed an already strained health care system and its provider base. About 4,500 physicians left the region, leaving 50% of children who previously had a health care provider without one. Most of
In 2006, the Merck Childhood Asthma Network and the
HEAL was an observational study designed to examine relationships between childhood asthma morbidity and the physical (allergens, mold, other exposures) and psychosocial (stress, social support, health care barriers) impacts of the post-Katrina environment. Another goal was to implement and assess a novel asthma counselor intervention that provided both asthma case management and guidance for environmental remediation. The intervention drew upon the National Cooperative Inner-City Asthma Study (NCICAS) (
Study design. HEAL was a pre-post interventional study that aimed to a) characterize relationships between environmental exposures and childhood asthma morbidity in post-Katrina NOLA; b) assess a novel asthma counselor intervention; and c) collect biological and environmental specimens to support future studies. Children with moderate-tosevcre asthma were recruited from NOLA schools, prescreened by telephone, and clinically evaluated to confirm eligibility and collect baseline data. Over 1 year, they received three home environment evaluations, astiima counseling, and another clinical evaluation. Asthma morbidity end points were collected quarterly (Figure 1). HEAL was approved by die NIEHS,
Population. Children were 4-12 years old, lived in NOLA, and had moderate-tosevere asthma as defined by the 2007 National Asthma Education and Prevention Program (National Heart, Lung, and
Recruitment. During the first 6 months of recruitment (February-August 2007), children in pre-kindergarten to grade 6 in public and parochial schools in
Information about HEAL was also disseminated through local radio and television stations, newspapers, and magazines. Pamphlets and posters were placed in schools, churches, community centers, pharmacies, clinics, emergency departments (EDs), and physician's offices. Community advisory group (CAG) members (described below) attended local events to discuss HEAL and pass out pamphlets.
Prescreening. Caretakers interested in HEAL were prescreened with a 15-min phone survey by trained nurses from
Baseline. At the baseline clinical evaluation, trained research assistants described HEAL to participants and answered their questions. Children were examined by physicians board-certified in pediatrics and in allergy and immunology for atopy and to confirm moderate-to-severe asthma. If final eligibility was met, caretakers were asked for written informed consent. Children were asked for oral (if < 7 years of age) or written (if £ 7 years of age) assent. Other baseline procedures included taking medical histories (emphasizing respiratory symptoms and medications), pulmonary function testing (PFT) (spirometry on children 6-12 years of age and peak flow on all children), and blood collection (16 mL) by venipuncture. Blood was used for complete blood cell counts and differentials, serum levels of total and allergen- and mold-specific IgE, and archiving for future studies.
Allergen skin testing was performed using a multi-test device (Multi-Test II;
Caretakers completed questionnaires for literacy, quality of life, children's behavior, attitudes about and knowledge of asthma, health care access and barriers, life events, and stress. All questionnaires in HEAL were administered to caretakers by trained research assistants, except for one that was validated as a self-administered questionnaire. Caretakers were also interviewed about their smoking habits and their children's symptoms, unscheduled ED or clinic visits, hospitalizations, medications, adherence, and home environments. Children completed verbal or written questionnaires, depending on age, about asthma attitudes and quality of life.
The baseline clinical evaluation took approximately 3 hr to complete. Afterward, the children's primary care physicians were sent letters summarizing the results.
Final clinical evaluation. Another clinical evaluation was conducted approximately 12 months after the baseline examination; this consisted of a physical examination, PFT, and blood collection (10 mL) for measuring serum levels of total and mold-specific IgE.
The questionnaires used at baseline were re-administered to caretakers by the trained research assistants during the 12-month follow-up. In addition, caretakers were administered a new post-Katrina needs assessment questionnaire that contained questions from the Kaiser Report (
Home environmental evaluations. Homes of HEAL children were evaluated at baseline and at 6 and 12 months by trained technician pairs. If a child relocated within 6 months after the baseline evaluation, the baseline evaluation was repeated in the new home. Evaluations focused on environmental hazards and allergens, and consisted of visual inspections, dust and air sampling, and face-to-face surveys of caretakers. The survey was a modified version of the
During the indoor inspection, technicians recorded evidence of moisture, water damage, environmental tobacco smoke, pests (cockroaches, rodents), mold, and other hazards. Air samples were collected from the living room, children's sleeping area/bedroom, and outside the home using Air-O-Cell spore traps (
During one of the home environment evaluations, technicians administered a onetime questionnaire (Home Remediation and Remodeling Questionnaire) to caretakers, which asked about post-Katrina renovations and mold remediation. Additional details about these evaluations are provided in the accompanying article (Grimsley et al. 2012).
Asthma counselor intervention. The goals of the asthma counselor intervention were to empower caretakers to better manage their children's symptoms, improve interactions with primary care providers, reduce home allergen levels, and manage psychosocial issues and stress resulting from Katrina. The intervention combined case management elements from NCICAS (
Most asthma counselors had master's degrees in health-related fields, backgrounds in counseling and public health, and experience working in community programs. They worked in teams with community health workers, who were high school graduates, worked for community-based organizations, and were familiar with NOLA communities. The teams underwent rigorous training and had lighter caseloads compared with NCICAS counterparts. Additional details about the asthma counselor model are provided in the accompanying article (Mitchell et al. 2012).
Compensation and retention. Participating caretakers received gift cards for completing the baseline clinical evaluation
Measures were taken to facilitate participation and minimize attrition. Caretakers were asked to update their contact information and that for family members and friends who served as back-ups at every point of HEAL contact (by asthma counselors, by home evaluators, by administrators of the quarterly surveys, and every time a HEAL caretaker contacted HEAL staff). Evening and weekend appointments were offered to accommodate caretakers' schedules. Transportation to and from appointments was prearranged and subsidized.
Community engagement. A CAG was assembled to engage local constituents and consisted of 1 5 members, including parents, individuals representing schools, faith-based and community groups, local businesses, medical clinics, and media. CAG members facilitated communication between communities and investigators, incorporated cultural and community views into HEAL, helped develop recruitment strategies and resolve problems, and represented HEAL at community events. The CAG met periodically with investigators, received reports on study progress, and disseminated results to local communities.
Health outcomes. Health outcomes data were collected from caretakers at baseline and 3, 6, 9, and 12 months after baseline using a brief (< 5 min) phone survey. The primary outcome was maximum symptom days (MSDs) for asthma. MSDs are determined as the number of days of the asthma symptom with the highest number of occurrences in the preceding 2 weeks. The different asthma symptoms were defined as a) the number of days with wheezing, chest tightness, and cough; b) the number of nights with disturbed sleep resulting from asthma; or c) the number of days of disrupted activities because of asthma. Secondary outcomes included the number of unscheduled ED and clinic visits due to asthma in the previous 3 months, the number of hospitalizations due to asthma in the previous 3 months, and the number of prednisone bursts (short high-dose steroid treatments used to calm asthma symptoms) in the previous month. The same outcomes also were assessed during clinical evaluations.
Statistical methods. We compared the characteristics of children from Orleans and Jefferson Parishes using f-tests (continuous outcomes) and Fisher's exact test (categorical outcomes). Parish-specific seasonal trends for symptoms and mold levels were analyzed using locally estimated scatterplot smoothing (LOESS) curves with 95% confidence intervals. Analyses were conducted using SAS version 9.2 (
Study design and recruitment. HEAL was initially designed as a randomized, controlled trial requiring 450 children to detect a significant reduction in asthma symptoms. Specifically, children with moderate-to-severe asthma were to be recruited from
Over the entire 1 -year recruitment period, 182 children were recruited into HEAL. A total of 105 children were recruited into HEAL during the second 6 months after the recruitment modifications were implemented. Of these 105 children, 49 came from
Despite the study modifications implemented above, we still realized after the first 6 months that we would not be able to recruit enough children to support the original randomized, controlled trial study design. Therefore, HEAL was transitioned to the observational study described in "Methods." This new design reduced the number of observations required to analyze study questions with adequate power (< 160 children for most comparisons). At the same time, the original study goals were maintained, the data already collected were used, and the impact on enrolled participants was minimized.
Over the 1-year recruitment period, 184 schools participated, including 89 schools in
Demographics. Children in HEAL were predominan dy African American (67%), and about 25% came from households with annual incomes <
Housing. Families relocated an average of three times since Katrina (Table 1). Most (64%) were living in single-family dwellings; 5% were living in
Health care access. Most children (85%) had a usual place of asthma care, but parish differences were observed. Only 80% of
Baseline asthma morbidity and allergic sensitization. HEAL children were symptomatic, averaging 6.64 MSDs; wheeze was the most common symptom, averaging 5.34 days in the previous two weeks (Table 2). Average FEV] (forced expiratory volume in 1 sec) levels were generally normal (91.05 ± 16.74% predicted), but the average FEV1ZFVC (forced vital capacity) ratio (78.22 ± 10.13) in HEAL children provided evidence for physiologic airway obstruction. Of the 182 children, 19% had an FEV1ZFVC ratio < 70%, indicating compromised pulmonary function. For allergic sensitization, 89% of children skin-tested positive to at least 1 of 22 allergens; 72% tested positive to at least 1 of 14 molds.
Baseline morbidity differed between parishes. Overall,
Study progress and attrition. Study activities concluded in September 2009. Of the 182 children enrolled, 161 (88%) completed the study; of those who did not, 5 withdrew, 3 moved out of NOLA, and 13 were lost to follow-up.
Hurricane Katrina caused catastrophic environmental devastation and disrupted the lives of people in NOLA. Flooding and rain destroyed much of the area's infrastructure, and residents suffered great losses, including homes, jobs, schools, support systems, and sometimes their lives. Concerns included the lack of health care and rising mold and allergen levels and their potential effects on children with asthma. HEAL was designed to characterize post-Katrina exposures of children with asthma and address their health care management. However, numerous challenges from the devastation were faced when implementing HEAL. Approximately 1 million residents had evacuated the area, and only about 50% had returned by mid-2007 (
An important modification that epitomizes the adaptive approach used in HEAL, and ultimately led to its success, was transitioning HEAL from a clinical trial to a 1-year observational study with postintervention follow-up. HEAL was initially designed as a randomized, controlled trial, but after 6 months, it became obvious that the recruitment numbers would not support this design. This problem was presented to the Data and Safety Monitoring Board, who worked with the investigators to modify the design and maintain the original study goals. With the new study design, data collection (morbidity, skin sensitivity, exposures) remained the same, and the quarterly end points could still be used to examine relationships between morbidity and exposures and to assess the effectiveness of the asthma counselor intervention.
Another important modification that led to HEAL's success was refined recruitment strategies. These refinements, especially the nurse-based recruitment, were effective and led to increased enrollment during the second 6 months. Nurse-based recruitment allowed us to target children with documented asthma, enabling more focused messaging that resonated effectively with caretakers. It also supported more efficient eligibility screening as interviewers worked with an asthmaenriched population rather than children with broad respiratory conditions. Other recruitment strategies (media, pamphlets, community engagement) raised public awareness of HEAL but resulted in only a small increase in enrollment (approximately 11%). Thus, active recruiting methods proved more successful in this environment, but passive recruiting helped to increase numbers somewhat. Ultimately, 182 children were enrolled in HEAL. Despite all the post-Katrina challenges faced by NOLA residents and HEAL scientists, this is one of the largest childhood asthma populations ever recruited from a single geographic location compared with other
Unfortunately, the enrollment expansion introduced parish-related demographic differences. Children from
One challenge of HEAL was the many activities required of participants in a postdisaster situation. Participants were required to take part in multiple, time-consuming activities over a short period of time during an otherwise stressful time in their lives. City infrastructure was still in disarray. Key public services (schools, transportation, utilities) were operating at less than half capacity, housing was scarce and expensive, unemployment was high, and federal money had not been distributed to areas most affected by Katrina (Liu et al. 2006). At the time of HEAL, 32% of NOLA residents said their lives remained "very disrupted" or "somewhat disrupted"; this value rose to 59% among African Americans (
HEAL children were more symptomatic at baseline (6.64 MSDs) compared with children from NCICAS (MSDs =5.18) and
Characterizing post-Katrina exposures and exploring their relationships to asthma was an important focus of HEAL that will be described in future publications. Testing for mold-asthma relationships is problematic because of limitations of mold methodologies and the lack of biomarkers (Brandt et al. 2006). Typically, mold is cultured from air (colony-forming units per cubic meter), but this procedure does not detect nonviable and unculturable species, resulting in exposure underestimations because nonviable mold also carries myco toxins that can trigger allergic reactions. Dust has been proposed as a better medium for mold analyses and might represent longer timeframes of potential exposures; when analyzed by PCR, nonviable and unculturable species in dust can be detected. In HEAL, we used a comprehensive, multipronged approach to characterize mold and other exposures. Different samples (air, dust, HEPA filter extracts) were collected and examined for many molds, allergens, ß-D-glucans, and endotoxin. When analyzed in conjunction with specific biomarkers (skin sensitivities, serum IgEs), these data will provide us with important insights into asthma-allergen-mold relationships. HEAL baseline findings of indoor mold and allergens are described in die accompanying article (Grimsleyetal.2012).
In addition to studying environmental relationships with asthma in a postdisaster setting, another goal of HEAL was to intervene in childhood asthma morbidity using a novel hybrid asthma counselor model that combined traditional case management with education and aid in reducing home exposures. We felt that incorporating allergen reduction measures in the model might increase its effectiveness considering the levels of mold, allergens, and other toxic exposures that were reported following Katrina. We found that HEAL children were highly sensitive to molds, compared with children in earlier studies. In
HEAL will provide valuable insight into postdisaster asthma-allergen relationships. HEAL was successful despite the extreme challenges faced by investigators in conducting HEAL and by participants in dealing with competing demands. These challenges were overcome by taking an adaptive approach that included refining recruitment processes, being flexible in scheduling, cross-communicating between study teams for the diligent follow-up of participants, and identifying and subsequently augmenting resources in problem areas. HEAL also underscores the importance of involving community members in the research process. CAG members represented diverse segments of the community, including schools, religious groups, health care providers, and parents. They helped to anticipate problems in implementing HEAL and provided insight into research design, recruitment and implementation, psychosocial and socioeconomic issues, and cultural norms.
The success of HEAL is measured in its sustainability. Pilot programs/studies are rarely sustained for multiple reasons, such as problems with buy-in and maintaining funding and the interest of supporters. However, because of its success and support from Merck Childhood Asthma Network, the HEAL hybrid asthma counselor model has been adopted by multiple public health programs, including those administered by
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Richard D. Cohn,5 L Faye Grimsley,6 Herman Mitchell,2 Jane El-Dahr,7 Yvonne Sterling,8 William J. Martin,9
Lu Ann White,6
1 Clinical Research Program,
Address correspondence to P.C. Chillada,
This project has been funded, in whole or in part, with federal funds from the
The authors declare they have no actual or potential competing financial interests.
HEAL was a collaboration of the following institutions, investigators, and staff:
Supplies were generously donated or discounted:
A variety of committees and working groups were formed for study development and implementation.
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