A Randomized Controlled Trial (RCT) Evaluating the Effects of Cool Roofs on Health Outcomes Using Smartwatches: a Global Multi-center Study
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- Enrollment
- 800
- Locations
- 4
- Primary Endpoint
- Heart rate
Study Overview
Brief Summary
Ambient air temperatures in Asian, Latin American, African, and Pacific climate hotspots have broken record highs in 2024. Solutions are needed to build heat resilience in communities and adapt to increasing heat from climate change. Sunlight-reflecting cool roof coatings may passively reduce indoor temperatures and energy use to protect home occupants from extreme heat. Occupants living in poor housing conditions globally - for example in informal settlements, slums, and low-socioeconomic households - are susceptible to increased heat exposure.
Heat exposure can instigate and worsen numerous physical, mental and social health conditions. The worst adverse health effects are experienced in communities that are least able to adapt to heat exposure. By reducing indoor temperatures, cool roof application may improve heart health, sleep and physical activity in household occupants.
The long-term research goal is to identify viable passive housing adaptation technologies with proven health benefits to reduce the burden of heat stress in communities affected by heat globally. To meet this goal, the investigators will use smartwatches to measure the effects cool roof application on heart health, sleep and physical activity in four urban climate hotspots: Ouagadougou, Burkina Faso; Hermosillo, Mexico; Ahmedabad, India; and Niue, Oceania.
Detailed Description
Increasing heat exposure from climate change is causing and exacerbating heat-related illnesses in millions worldwide - particularly in low resource settings. June 2024 was the 13th consecutive hottest month on record globally - shattering previous records. Heat exposure can instigate and worsen numerous health conditions. Adaptation is essential for protecting people from increasing heat exposure. The built environment, especially homes, are ideal for deploying interventions to reduce heat exposure and accelerate adaptation efforts. However, evidence is currently lacking on a global scale - generated through empirical studies - guiding the uptake of interventions to reduce indoor heat stress in low resource settings.
Sunlight-reflecting cool roof coatings passively reduce indoor temperatures and lower energy use, offering protection to home occupants from extreme heat. Continuous monitoring of health and wellbeing using smartwatches can provide insight into important parameters such as heart rate, sleep and physical activity - which are all affected by heat. Using smartwatches, the investigators will also continuously measure health and wellbeing outcomes during the day and night. The investigators will conduct a global multi-centre study to investigate the effects of cool-roof use on heart rate, sleep and physical activity in four urban climate hotspots - Ouagadougou, Burkina Faso (sub-Saharan Africa), Ahmedabad, India (Asia), Niue (Oceania), and Sonora, Mexico (Latin America). These sites represent hotspots where people experience a triple burden from heat exposure, chronic health issues and vulnerable housing conditions (slums, informal settlements and low socioeconomic housing). They also exhibit diversity in climate profiles, housing typology, level of socioeconomic development, population density and rates of urbanisation.
This trial will quantify whether cool roofs are an effective passive home cooling intervention with beneficial health effects for vulnerable populations in four locations. Findings will inform global policy responses on scaling cool roof implementation to protect people from increasing heat exposure driven by climate change.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Prevention
- Masking
- Double (Investigator, Outcomes Assessor)
Masking Description
Trial participants will be aware of the intervention to which they have been allocated, and the research fieldworkers will be aware of the intervention allocation. The trial steering committee members and trial statistician will remain blinded until the end of trial period and data collection.
Eligibility Criteria
- Ages
- 18 Years to — (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Permanent household resident
Exclusion Criteria
- •Roof damage, inaccessible or instability of roof adversely affecting cool roof coating application.
- •Participant unable to provide written/verbal informed consent. Participants will be excluded if they are not willing or able to wear a smartwatch.
- •In Mexico and Niue, participants will be excluded if they do not have a smartphone with an internet connection that can connect to the smartwatch.
- •Only one participant per household.
Arms & Interventions
Cool roof
Households will receive sunlight reflecting 'cool roof' coating on their roofs.
Intervention: Cool roof (Other)
No cool roof
No cool roof application. Households will keep their original roofing for the duration of the trial.
Outcomes
Primary Outcomes
Heart rate
Time Frame: Smartwatches will be worn for two consecutive weeks per month. Eight measurement points will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Heart rate in beats per minute measured at 15-second intervals using Garmin Vivosmart 5 devices.
Secondary Outcomes
- All-day steps(Smartwatches will be worn for two consecutive weeks per month. Eight measurement points will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.)
- Active minutes(Smartwatches will be worn for two consecutive weeks per month. Eight measurement points will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.)
- Distance walked(Smartwatches will be worn for two consecutive weeks per month. Eight measurement points will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.)
- Moderate-intensity activity minutes(MeasuSmartwatches will be worn for two consecutive weeks per month. Eight measurement points will be taken: one at barements will be taken continuously for 12 months. Participants will be asked to wear their smartwatch for at least two weeks every month.)
- Vigorous-intensity activity duration(Smartwatches will be worn for two consecutive weeks per month. Eight measurement points will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.)
- Sleep quantity(Smartwatches will be worn for two consecutive weeks per month. Eight measurement points will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.)
- Time in sleep stages(Smartwatches will be worn for two consecutive weeks per month. Eight measurement points will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.)
- Awake duration(Smartwatches will be worn for two consecutive weeks per month. Eight measurement points will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.)
- Sleep score(Smartwatches will be worn for two consecutive weeks per month. Eight measurement points will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.)
Investigators
Aditi Bunker
Co-Principal Investigator
University of Auckland, New Zealand