Health Impacts of a Climate Change Adaptation Strategy to Address Drinking-water Salinity in Coastal Bangladesh
试验速览
- 阶段
- 不适用
- 入组人数
- 1,200
- 试验地点
- 2
- 主要终点
- reduction of mean systolic blood pressure among the >20 populations
研究概览
简要总结
Background (brief):
- Burden:
Excessive salinity is common in groundwater aquifers across south-western coastal Bangladesh. Higher adult mean systolic and diastolic blood pressure and increased risk of gestational hypertension has been observed among those who drank tube-well water with high sodium content. 2. Knowledge gap:
Managed Aquifer Recharge (MAR) systems, that inject freshwater into shallow aquifers, reduce drinking water salinity, have been successfully installed in the south-western area, providing year-round freshwater. However, the health benefits and risks of MAR water have not been measured. 3. Relevance:
If drinking MAR water can reduce hypertension in adults and pregnant women, while showing minimal risk of microbiological and chemical contamination, scale up can be considered.
Hypothesis (if any):
Mean systolic and diastolic blood pressure will be lower among the adult population who drink MAR water compared to people drinking saline or brackish groundwater Objectives: To determine
- If providing access to MAR water for drinking and food preparation reduces blood pressure among the adult population > 20 years of age.
- If providing access to MAR water for drinking and food preparation during pregnancy can reduce blood pressure among pregnant women.
- If MAR water is contaminated with E coli and fecal coliforms.
- Whether the MAR water is contaminated with dissolved constituents mobilized from aquifer sediments that are known to be harmful to human health.
Methods:
A stepped-wedge RCT will be conducted among communities before and after the intervention roll out. Study investigators will collect baseline information from all sites in the first monthly block (step) when no one will drink MAR water. There will be promoters who will convey messages regarding exclusive use of MAR water for drinking and cooking, at home and elsewhere. Measurements will be made by trained research assistants once every month. MAR water, pond water, groundwater and household stored water samples will be collected and tested once every month.
详细描述
Study sites:
The proposed study will be a stepped-wedge RCT that will be implemented in 20 MAR communities All 20 MAR communities will gradually have access to MAR water, but their access will be at different time periods or steps. Therefore, each MAR site will contribute data for both the intervention and the control time periods. There will be five, monthly steps in the stepped wedge trial. In the first monthly step, none of the communities will have MAR water available for drinking and the baseline information will be collected from all communities. During each subsequent month, five MAR communities will be randomly assigned to receive the intervention. In the last (fifth) monthly step, all the communities will have access to MAR drinking water. Blood pressure of all enrolled participants will be measured during each step. Animal and human studies suggest change in salt load changes blood pressure within few hours, and a meta-analysis of randomized trials suggest modest reduction in salt intake for four or more weeks causes significant reduction in blood pressure at the population-level. Therefore, the investigators will use an interval of at least one month between access to MAR water and first post-intervention blood pressure measurement, and between two consecutive blood pressure measurements.
This study protocol has been approved by the icddr,b Ethical Review Committee. Informed written consent will be taken from all participants and household heads.
Site selection and randomization:
The 30 MAR communities that are ready to roll out intervention (access to MAR water to the community) are located in rural areas in the three districts and 20 MAR communities which can be reached most effectively based on geographical location will be selected. Water samples from the selected 20 MAR sites will be collected every month for one year from June, 2016 to May, 2017 to capture the seasonal variation of microbiological and chemical water quality. Human health data and biological specimens from the enrolled participants from within the catchment area of the selected 20 sites will be collected from December, 2016 to May, 2017.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Prevention
- 盲法
- None
入排标准
- 年龄范围
- 20 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Participants >20 years (both male and female)
- •Pregnant women
排除标准
- 未提供
研究组 & 干预措施
Managed Aquifer Recharge water
All the study population will receive the intervention by a random allocation over the study period. The study participants will be in both intervention and control at different times.
干预措施: Managed Aquifer Recharge water (Other)
Control
All the study population will receive the intervention by a random allocation over the study period. The study participants will be in both intervention and control arms at different times.
干预措施: Managed Aquifer Recharge water (Other)
结局指标
主要结局
reduction of mean systolic blood pressure among the >20 populations
时间窗: 5 months
次要结局
未报告次要终点