DIY Indoor Air Cleaner Study in Rural and Urban Communities in Colorado

Our Phase II project is designed using the RE-AIM (Reach, Effectiveness, Adoption, Implementation, and Maintenance) and PRISM (Practical, Robust, Implementation, Sustainability, and Monitoring) frameworks to evaluate each stage of the implementation process. RE-AIM will assess reach and effectiveness, as well as measures of implementation and sustainability. PRISM will aid in design and sustainability, as we seek to better understand and incorporate community perspectives and factors related to the external environment and implementation and sustainability infrastructure. This holistic view of implementation will inform sustainability and scalability to other communities.

Hybrid Type 1 Effectiveness-Implementation Study: Household Do it Yourself Air Cleaner (DIYac) Intervention While there is abundant evidence on the efficacy of a DIYac in reducing particulate matter (PM) in well-controlled environments, there is a lack of data on their effectiveness when deployed in real world settings. A Hybrid Type 1 (HT1) design is thus appropriate for our study, which tests the effectiveness of DIYac when implemented in rural and urban low-resource populations (WD and SLV). Effectiveness outcomes include behaviors (DIYac correct use), air quality (measured as PM), and physical and mental health indicators. Following HT1 design principles, we will integrate a process evaluation, guided by the RE-AIM and PRISM frameworks, to identify barriers and facilitators to broader, scalable implementation of the intervention as PM exposure mitigation strategy.

Stepped Wedge Design We will recruit and enroll a total of 550 households (WD: n=300; SLV: n=250) using a stratified random selection from an enumerated address for both communities derived from publicly available tax parcel mailing lists. Addresses will be stratified by county (SLV) and neighborhood (WD) to ensure geographic representation for the sample in each community. After selection, households within each community will be randomly assigned to two groups which determine at what point in the study the intervention is initiated. Given the high prevalence of related health outcomes (e.g. asthma, chronic obstructive pulmonary disease (COPD)), we anticipate that a random sample from each stratum will include key groups (outdoor workers (20-60%), chronic diseases (12%), aging (30%), and household with children (30%)).

Natural Experiment Readiness Our project is designed to facilitate a rapid response to an event, such as a wildfire or dust storm, by employing a flexible and adaptive framework that can quickly mobilize resources and data collection efforts. Previous work by research team members demonstrates our adaptability to launch responsive, multidisciplinary research following events; we are well-equipped to apply similar approaches to assess the effectiveness of DIYac in mitigating exposure to elevated PM inside homes. By using a natural experiment design, the research can compare households with and without DIYac interventions and track emergent and urgent care trends, offering crucial insights into the potential for widespread implementation of these systems in at-risk regions.

Study Aims \& Research Questions

Our study will address the following three aims and associated research questions (RQs):

Aim 1: Evaluate impacts of DIYac on exposure to indoor PM associated with ambient PM.

RQ2. (Effectiveness) Does adoption and use of DIYac reduce indoor PM levels, attributed to ambient PM? Hypothesis 2a: DIYac use will lead to significant decline in indoor PM levels. Hypothesis 2b: During an elevated PM event, households with DIYac will experience significantly lower indoor PM than those without DIYac. Note: this hypothesis will only be answerable if an event occurs during the intervention period.

Aim 2: Evaluate impacts of intervention on DIYac adoption, use, and maintenance.

RQ1a. (Effectiveness) Do households that are provided a DIYac successfully adopt and consistently use and maintain these filters as recommended? Hypothesis 2a: Households in the intervention condition (Group 1) will have significantly higher rates of adoption of the DIYac use than those in Group 2 (baseline). Hypothesis 2b: After intervention phase households will report improved self-efficacy, sense of agency, and hopefulness than pre-intervention.

RQ1b. (Implementation) What barriers and facilitators influence DIYac adoption, use, and maintenance across rural and urban low-resource households? Hypothesis 1b: Barriers and facilitators to DIYac implementation will include similar factors across sites, including costs (electricity and maintenance) and noise, as well as some factors that are household-specific (person with asthma) or regional (lower access to materials in urban areas). Community engagement and program design can identify strategies to address these barriers.

Aim 3: Evaluate impacts of DIYac on health outcomes (physical and mental health) and biomarkers of exposures (urinary markers).

RQ3. (Effectiveness) Does adoption and use of DIYac improve self-reported and measured physical and mental health indicators and urinary biomarkers of exposure to PM? Hypothesis 3a: DIYac use is associated with improved metrics of physical health and mental health. Hypothesis 3b: During an elevated PM event, households with DIYac will have improved metrics of physical and mental. Note: this hypothesis will only be answerable if a wildfire smoke event occurs during the intervention period.