Lessons Learned for the Study of Childhood Asthma from the Centers for Children’s Environmental Health and Disease Prevention Research

Abstract

The National Children’s Study will address, among other illnesses, the environmental causes of both incident asthma and exacerbations of asthma in children. Seven of the Centers for Children’s Environmental Health and Disease Prevention Research (Children’s Centers), funded by the National Institute of Environmental Health Sciences and the U.S. Environmental Protection Agency, conducted studies relating to asthma. The design of these studies was diverse and included cohorts, longitudinal studies of older children, and intervention trials involving asthmatic children. In addition to the general lessons provided regarding the conduct of clinical studies in both urban and rural populations, these studies provide important lessons regarding the successful conduct of community research addressing asthma. They demonstrate that it is necessary and feasible to conduct repeated evaluation of environmental exposures in the home to address environmental exposures relevant to asthma. The time and staff required were usually underestimated by the investigators, but through resourceful efforts, the studies were completed with a remarkably high completion rate. The definition of asthma and assessment of disease severity proved to be complex and required a combination of questionnaires, pulmonary function tests, and biologic samples for markers of immune response and disease activity. The definition of asthma was particularly problematic in younger children, who may exhibit typical asthma symptoms sporadically with respiratory infections without developing chronic asthma. Medications confounded the definition of asthma disease activity, and must be repeatedly and systematically estimated. Despite these many challenges, the Children’s Centers successfully conducted long-term studies of asthma.

Air pollution and respiratory symptoms among children with asthma: Vulnerability by corticosteroid use and residence area

“…An intense effort was made to maintain contact and involvement with enrolled families. Retention rates and degree of data missingness are similar to other reports in the literature (Eggleston et al, 2005; Mortimer et al, 2002). …”

“…Although many challenges with recruitment and retention exist for a study of this length and intensity (Eggleston et al, 2005), the CBPR approach and guidance from our community partners was instrumental in addressing these challenges in a city where many families struggle with financial and social stressors. An intense effort was made to maintain contact and involvement with enrolled families.…”

Lessons learnt on recruitment and fieldwork from a pilot European human biomonitoring survey

“…In two countries the information on the analytical results that all participants received served as the only incentive. But as Eggleston et al (2005) reported, this is not negative: Sometimes information provided to the participants attracted them most to the study, more than other offered incentives. Theses authors also described that reimbursements for electricity costs during the survey (up to US $200) or reimbursements for travel expenses are common.…”

At What Age Can Children Report Dependably on Their Asthma Health Status?

“…The CHSA-C was adapted from an existing parent report instrument, the Children's Health Survey for Asthma (CHSA); the strong validity and reliability of the CHSA were reported previously, 28 and the instrument has been used in numerous asthma studies. [29][30][31][32] We conducted intensive oneon-one interviews with young children before data collection, to make practical, child-friendly, questionnaire modifications (such as a calendar review to facilitate understanding of a 2-week recall period and visual representation of Likert-type response choices). Details about the CHSA, the development of the CHSA-C, and the data collection process are available from the authors at the American Academy of Pediatrics.…”