Participants and settings
The study used a quasi-experimental design to examine the effectiveness of the asthma home-based education intervention by comparing health outcome changes between the intervention and control groups. Eligible participants included families with children ages 1 to 17 diagnosed with asthma by a healthcare professional and living in Hidalgo County, Texas. In 2017, Hidalgo County had a population of 860,661 residents and a poverty rate of 31.2%, where 92.2% of this population identifies as Hispanic [22]. The childhood asthma prevalence for Hidalgo County was about 9.4%, higher than the national (8.3%) and state (7.6%) prevalence in 2016 [1, 9]. The research team acquired a list of schools in the county’s Independent School District (ISD) through the district’s health director, and randomly and blindly assigned the 19 total schools in this list to either an intervention group or control group. Children diagnosed with asthma attending any of the district’s schools were invited to participate in the study, with informed consent obtained from each child’s parent/guardian. Parents who did not sign the consent form provided explanations such as “My child’s health is controlled,” “I already know about asthma,” or “I do not have time to participate because I work all day.” Two community health workers (CHWs) were assigned to each intervention and control group to administer the entire study protocol, including patient management, home visits, the educational intervention, and pre/post-surveys. From May 2016 to June 2018, the education program was implemented, where two CHWs were assigned to an intervention or control group, and visited individual families at baseline and in follow-up visits every 3 months. The Institutional Review Boards of Texas A&M University reviewed and approved the study protocol.
Intervention
The home-based asthma educational intervention was based on the Asthma and Healthy Homes curriculum certified by the Texas Department of State Health Services. The intervention aimed to teach families how to more effectively manage their child’s asthma, and create a healthier home environment. It included the following components: asthma signs and symptoms, asthma management, identifying common asthma triggers, correct use of asthma medications, emergency actions in case of asthma attacks, and fundamental components of an asthma action plan [23]. The curriculum also included content from the Seven Principles of Healthy Homes, a program developed by the National Healthy Homes Training Center and Network to reduce hazardous exposure in the household and learn how to keep the home dry, clean, ventilated, safe, pest-free, and contaminant-free [24].
The Asthma and Healthy Homes Curriculum Manual includes detailed steps for providing thorough participant training, centering the same topics included in the curriculum. Specialized instructors use comprehensive Asthma and Healthy Homes’ curriculum training modules to train Community Health Workers on how to teach the same content to the study’s participants [25]. CHW training consists of lectures, discussions, class participation/exercises, case studies, and Question & Answer sessions. After completed training, CHWs provide 60–90 min education sessions to children and families in the intervention group in either English or Spanish, utilizing the same curriculum. For the control group, CHWs only provided necessary educational materials related to asthma management without offering any direct education. CHWs provided participants in both the intervention and control groups with an allergen-proof mattress, pillow encasing, and non-chemical cleaner recipes, as well as instructions for how to use them.
Measurements
The research team collected participants’ demographic and socioeconomic information and tracked their changing health outcomes between initial and follow-up visits using the Children’s Health Survey for Asthma, a validated and standardized tool developed by the American Academy of Pediatrics. The survey instrument conveyed health outcomes such as number of asthma attacks, hospitalizations, and emergency room (ER) visits during the last 4 weeks. The tool also asked participants to measure five health outcomes from a positive attribute of 0 (least) to 100 (most): these five health outcomes included physical health of child (PH), activities of children (AC), activities of family (AF), emotional health of children (EC), and emotional health of family (EF) [13, 26]. When measuring demographic and socioeconomic information, the survey first asked participants questions about the child participant, such as the child’s age of asthma diagnosis (continuous), the child’s gender (boy or girl), the child’s race/ethnicity (Hispanic or non-Hispanic), and if the child used inhaler steroids for more than 2 weeks (yes or no). Then, the survey focused on the family unit, focusing on family history of allergies (yes or no), household smoking (yes or no), parent/guardian’s marital status (married or non-married), household income (less than 15,000 or greater than / equal to $15,000), and type of insurance (public insurance or private insurance/self-pay).
At the baseline home visit by CHWs, all of the participants in both groups completed a pre-test and the CHSA survey. The CHW then provided 60–90 min in-person educational sessions with participants in the intervention group; those in the control group only received basic informational material with no direct education. Then, participants completed the same survey 3 months post-baseline during the follow-up visit. The changes in health outcomes from the initial and follow-up visits were compared between the intervention and the control groups.
Statistical analysis
Descriptive statistics of the study population were calculated to estimate mean and standard deviation (SD) for continuous variables, or percentages for categorical variables. To compare differences in health outcomes between baseline and follow-up of intervention and control groups, change of values were calculated by subtracting baseline values from the follow-up values. The Pearson chi-squared tests for categorical variables and the Student t-tests for continuous variables were used to compare the baseline characteristics between participants with asthma education curriculum and those without the curriculum. Two sample t-tests were also performed to compare changes in each health outcome between intervention and control groups.
We used multiple ordinary least squares (OLS) regression models to analyze the associations between the educational intervention and change in health outcomes. Children’s age when diagnosed with asthma, use of steroids, household income, family history of allergy, and type of insurance were included in the models as confounders. With the control group, the participants without direct educational intervention, as the reference group, we calculated the point estimates and 95% confidence intervals (CIs) of the coefficient for health outcomes in association with the intervention after adjusting for confounding factors. All statistical analyses were performed by using R, version 3.5.1. A p-value < 0.05 was considered significant.