Wood Smoke Interventions in Native American Populations

Study Overview
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Brief Summary
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A critical need exists for efficient community-based interventions aimed at reduction of environmental exposures relevant to health. Biomass smoke exposures due to residential wood heating are common among rural Native American communities, and such exposures have been associated with respiratory disease in susceptible populations. In many of these communities wood stoves are the most economic and traditionally preferred method of residential heating, but resource scarcity can result in burning of improper wood fuels and corresponding high levels of indoor particulate matter. Community-based participatory research techniques will be used to adapt intervention approaches to meet the cultural context of each participating community. At the community level, investigators will facilitate local development of a tribal agency-led wood bank program ensuring that elderly and/or persons with need have access to dry wood for heating. At the household level, investigators will use a three arm randomized placebo-controlled intervention trial to implement and assess education/outreach on best burn practices (Tx1). The content and delivery strategies of the education intervention will be adapted to each community according to stakeholder input. This educational intervention will be evaluated against an indoor air filtration unit arm (Tx2), as well as a placebo arm (Tx3, sham air filters). Tx3 will be used in comparison with the other two treatment arms to evaluate the penetration and efficacy of the community-level wood bank program. Outcomes will be evaluated with respect to changes in pulmonary function measures and respiratory symptoms and conditions among household elders. The investigators hypothesize that locally-designed education-based interventions at the community and household levels will result in efficacious and sustainable strategies for reducing personal exposures to indoor particulate matter, and lead to respiratory health improvements in elderly Native populations. This study will advance knowledge of cost-effective environmental interventions within two unique Native American communities, and inform sustainable multi-level strategies in similar communities throughout the US to improve respiratory health among at-risk populations.

Detailed Description
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Rural Native American (NA) communities experience disproportionate disease burden compared to other US populations, with poor indoor air quality resulting from in-home biomass smoke exposures (residential wood stoves) a likely contributor to these health burden discrepancies. Epidemiological studies support the etiological association between indoor biomass smoke exposure and several domains of global disease burden, particularly with respect to pediatric respiratory tract infections and adult chronic obstructive pulmonary disease (COPD) and chronic bronchitis. Elderly populations are particularly susceptible to chronic respiratory conditions, and declining pulmonary function is associated with increased morbidity and mortality. Randomized trials in developing countries have demonstrated the impact that improved cookstove technologies have in reducing biomass smoke exposures and children's risk of acute respiratory infection. However limited knowledge is available regarding the potential improvements in NA elderly populations following wood stove interventions. Today, a critical need exists for efficient community-based interventions aimed at promoting healthy indoor environments in at-risk communities. Financial and logistical barriers that currently exist in rural and economically disadvantaged NA communities prohibit the implementation and sustainability of many environmental health interventions. Regarding wood stoves, qualitative input from experts and Native communities underscores the need for innovative low-cost, sustainable interventions targeting the reduction of in-home biomass smoke exposures. In this proposal, investigators will test community-level and education-based household-level strategies aimed at promoting and implementing best-burn practices to improve air quality and respiratory health in at-risk elderly populations. This proposal represents a multidisciplinary collaboration between university and tribal stakeholders from two Native American Reservations to develop, adapt, implement, and evaluate a two-level intervention to reduce exposure to indoor biomass smoke and improve respiratory health among elderly tribal members. Community-based participatory research techniques will be used to adapt intervention approaches to meet the cultural context of each participating community. At the community level, investigators will facilitate local development of tribal agency-led wood yard and distribution programs ensuring that elderly and/or persons with need have access to dry wood for heating. With community advisory guidance, investigators will use a three arm randomized placebo-controlled intervention trial to implement and assess education on best burn practices (Tx1) at the household level. This educational intervention will be evaluated against an indoor air filtration unit arm (Tx2), as well as a placebo arm (Tx3, sham air filters). Tx3 will be used in comparison with the other two treatment arms to evaluate the penetration and efficacy of the community-level fuel program. Outcomes will be evaluated with respect to changes in markers of respiratory health among elders and changes in indoor air quality (PM2.5). The investigators hypothesize that locally-designed education-based interventions, in the context of a community-based strategy focused on wood fuels, will result in efficacious and sustainable strategies for reducing personal exposures to indoor biomass smoke PM2.5 and lead to respiratory health improvements in elderly NA populations. Specific Aims are as follows: Aim 1. Facilitate the tribally-centered development, adaption, implementation, and evaluation of community-level wood yard and distribution programs for participating tribal households. Aim 2. Facilitate the development, adaptation, implementation, and evaluation of household-level education strategies targeting best-burn practices (Tx1) for each participating tribal community. Aim 3. Compare effectiveness, both within and between communities, of household-level interventions among elderly adults participating in a three-arm randomized placebo-controlled trial. Aim 3a. Compare group changes in pulmonary function and respiratory symptoms and infections. Aim 3b. Compare group changes in indoor and personal PM2.5 exposures. Aim 4. Evaluate penetration, acceptance, and sustainability of community- and household-level strategies using both qualitative and quantitative data generated in collaboration with tribal community advisory boards and research participants. Impact. The long-term goal of this project will be to reduce mortality and morbidity in NA communities from exposures related to residential home heating. This study will advance knowledge of effective interventions within two unique NA Reservations and describe improvements in sub-clinical indicators of pulmonary health in susceptible elderly populations. Reducing in-home wood smoke exposures through community level facilitation of access to proper fuels and introduction of sustainable, culturally appropriate best-burn practices will inform strategies for translation to other NA communities or similar rural and underserved populations.

Official Title
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Residential Wood Smoke Interventions Improving Health in Native American Populations

Conditions
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Respiratory; Disorder, Functional, Impaired, Respiratory Infection Other

Intervention / Treatment
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* Behavioral: Education (Tx1)
* Device: Air Filtration Unit Treatment (Tx2)
* Device: Placebo Intervention (Tx3)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Tribal member from one of the two study regions Age 55 years or older. Utilize a wood stove as the primary heating source. Capable and willing to record symptom data and wood stove usage data, as well as complete pulmonary function testing (i.e., spirometry). Exclusion Criteria:

Ages Eligible for Study
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Minimum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Education (Tx1)<br>Education on best burn practices | Behavioral: Education (Tx1)<br>* Education on best burn practices<br>|
| Active Comparator: Air Filtration Unit Treatment (Tx2)<br>A 20 x 18 Filtrete air filtration unit (3M, St. Paul, MN) will be placed in the same room as the wood stove. | Device: Air Filtration Unit Treatment (Tx2)<br>* A 20 x 18 Filtrete air filtration unit (3M, St. Paul, MN) will be placed in the same room as the wood stove<br>|
| Sham Comparator: Placebo Intervention (Tx3)<br>A 20 x 18 Filtrete air filtration unit will be installed within the wood stove home. Instead of a high efficiency filter, the units will utilize a placebo filter. | Device: Placebo Intervention (Tx3)<br>* A 20 x 18 Filtrete air filtration unit will be installed within the wood stove home. Instead of a high efficiency filter, the units will utilize a placebo filter.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-intervention FEV1 | Mean of up to two post-intervention measures of forced expiratory volume at one second (FEV1), liters | Each participant was followed during a pre-intervention baseline (Winter 1) and a post-intervention follow-up period (Winter 2). Health measures were collected at two visits during both winter periods with each visit separated by at least three weeks. | 
| Post-intervention FVC | Mean of up to two post-intervention measures of forced vital capacity (FVC), liters | Each participant was followed during a pre-intervention baseline (Winter 1) and a post-intervention follow-up period (Winter 2). Health measures were collected at two visits during both winter periods with each visit separated by at least three weeks. | 
| Post-intervention FEV1/FVC Ratio | Mean of up to two post-intervention measures of forced expiratory volume at one second (FEV1) / forced vital capacity (FVC) | Each participant was followed during a pre-intervention baseline (Winter 1) and a post-intervention follow-up period (Winter 2). Health measures were collected at two visits during both winter periods with each visit separated by at least three weeks. | 
| Post-intervention Systolic Blood Pressure | Mean of up to two post-intervention measures of systolic blood pressure, millimeters of mercury (mmHg) | Each participant was followed during a pre-intervention baseline (Winter 1) and a post-intervention follow-up period (Winter 2). Health measures were collected at two visits during both winter periods with each visit separated by at least three weeks. | 
| Post-intervention Diastolic Blood Pressure | Mean of up to two post-intervention measures of diastolic blood pressure, millimeters of mercury (mmHg) | Each participant was followed during a pre-intervention baseline (Winter 1) and a post-intervention follow-up period (Winter 2). Health measures were collected at two visits during both winter periods with each visit separated by at least three weeks. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-intervention Indoor Fine Particulate Matter (PM2.5) | Post-intervention average Indoor fine particulate matter (PM2.5) concentration | Each participant was followed during a pre-intervention baseline (Winter 1) and a post-intervention follow-up period (Winter 2). Indoor 48-hour PM2.5 average concentration was measured at two post-intervention visits separated by at least three weeks. |