An interventional study of Cool roof in Resting Heart Rate, Blood Glucose Control and Depression, sponsored by Aditi Bunker. Not yet recruiting at 1 site in Fiji. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-18.
Sponsored by Aditi Bunker · Not applicable, Interventional, and Prevention
Ambient air temperatures in Fiji are increasing due to climate change. Solutions are needed to build heat resilience in communities and adapt. 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 in Fiji 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 use can promote physical, mental and social wellbeing in household occupants.
The long-term research goal of the investigators is to identify viable passive housing adaptation technologies with proven health benefits to reduce the burden of heat stress in communities affected by heat in Fiji. To meet this goal, the investigators will conduct a cluster-randomized controlled trial to establish the effects of cool roof use on health, indoor environment and economic outcomes in Tavua, Fiji.
Increasing heat exposure from climate change is causing and exacerbating heat-related illnesses in millions worldwide - particularly in low-resource settings. Heat exposure can instigate and worsen health conditions, including cardiovascular, metabolic, endocrine and respiratory disease, heat-related illnesses, pregnancy complications, and mental health conditions. Adaptation is essential for protecting people from increasing heat exposure. The built environment, especially homes, is ideal for deploying interventions to reduce heat exposure and accelerate adaptation efforts. However, there is currently a lack of global, empirical evidence guiding the uptake of interventions to reduce heat stress in low-resource settings.
Cities and towns of LMIC are among the most vulnerable to the adverse impacts of climate change and are likely to experience increases in ambient air temperature over the coming decades. People in Fiji are exposed to year-round heat and low humidity. The combined burden of heat and NCDs places Fiji's population at greater risk of adverse health effects from heat extremes.
Sunlight-reflecting cool roof coatings passively reduce indoor temperatures and lower energy use, offering protection to home occupants from extreme heat. The investigators therefore aim to conduct a cluster-randomized controlled trial investigating the effects of cool-roof use on health, environmental and economic outcomes in Fiji.
The trial will quantify whether cool roofs are an effective passive home cooling intervention with beneficial health effects for vulnerable populations in Fiji. Findings will inform regional policy responses to scale cool roof implementation and protect people from increasing heat exposure driven by climate change.
8,577 studies on the registry are indexed under Depression; 1,720 are open to participants now.
This study's planned enrollment of 800 is above the median of 81 across 7,063 interventional studies indexed under Depression.
Browse Depression studies →Aditi Bunker is the lead sponsor of 7 studies on the registry; 3 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Households will receive sunlight reflecting 'cool roof' coating on their roofs.
Other: Cool roof
No cool roof application. Households will keep their original roofing for the duration of the trial.
Cool roofs are a heat-reflecting material that can be applied to existing household roofing in the form of a liquid-applied membrane. Cool roofs work by increasing solar reflectance (the ability to reflect the visible wavelengths of sunlight, reducing heat transfer to the surface) and thermal emittance (the ability to radiate absorbed solar energy) thereby reducing the amount of heat transferred into the home.
Resting heart rate
Resting heart rate in beats per minute measured as the average of three readings in the left arm over one hour using portable automated sphygmomanometers.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Blood glucose control
Three month average of blood glucose in mmol/mol measured as glycosylated hemoglobin (HbA1c) using capillary blood and the HemoCue® HbA1c 501 System.
Time frame: Two measurements will be taken: one at baseline and one in the last month of three consecutive hottest months.
Depression
Self-reported presence and frequency of symptoms of depression assessed using aggregate score of the Patient Health Questionnaire 9 (PHQ-9). Minimum score of 0 and a maximum score of 27 with a higher score meaning a worse outcome.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Heat-related symptoms
Self-reported heat-related symptoms in the past month, assessed using a recall questionnaire.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Physician diagnosed heat-related illnesses
Self-reported new diagnosis from a medical practitioner of a heat-related illness in the last month assessed using a recall questionnaire.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Food insecurity
Self-reported experience based measure of individual food security assessed using the Food Insecurity Experience Scale (FIES).
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Diet quality
Self-reported individual food group consumption in the previous 24 hours assessed using the Diet Quality Questionnaire (DQQ).
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Hospitalization
Self-reported overnight hospital stay in the past four weeks assessed using a recall questionnaire.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Health-related quality of life
Current self-reported health-related quality of life assessed using the EuroQol EQ-5D-5L quality assessment tool. The minimum and maximum scores for the EuroQol EQ-5D-5L quality assessment tool are -0.59 and 1, respectively. A score of 1 represents the best possible health state, while scores below 0 indicate health states that are considered worse than death.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Indoor thermal comfort
Self-reported household heat, humidity and comfort experience over the last four weeks assessed using a recall questionnaire.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Coping ability
Self-reported coping strategies for high indoor temperatures assessed using a recall questionnaire.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Life satisfaction
Current self-reported life satisfaction assessed using the World Values Survey. Values can range from 1 to 10 with a higher score representing greater life satisfaction.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Healthcare provider utilization
Self-reported healthcare provider utilization in the past four weeks assessed using a recall questionnaire.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Systolic Blood Pressure
Maximum blood pressure (mmHg) during systole measured as the average of three readings in the left arm over one hour using Blip portable automated sphygmomanometers.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering the three consecutive hottest months and four alternate months.
Diastolic Blood Pressure
Minimum blood pressure (mmHg) during diastole measured as the average of three readings in the left arm over one hour using Blip portable automated sphygmomanometers.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering the three consecutive hottest months and four alternate months.
Intimate partner violence
Recall questionnaire assessing the presence or abscence intimate partner violence in the past 4 weeks.
Time frame: Eight measurements: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Inner Ear Canal Temperature
Internal body temperature (℃) measured once using Braun digital ear thermometer.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering the three consecutive hottest months and four alternate months.
Dehydration
Dehydration as indicated by urine specific gravity ≥1.020 measured as urine specific gravity using Siemens Multistix SG dipstick.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Sleep quality
Self-reported sleep distrubance assessed using the Athens Insomnia Scale (AIS). Values range from 0 to 24 with a higher score indicating a worse outcome.
Time frame: Eight measurements: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Aggression
Self-reported personal aggresion assessed using the Buss-Perry Aggression Questionnaire-Ultra Short Form (BPAQ-ML).
Time frame: Eight measurements: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.
Productivity
Self-reported job absenteeism and presenteeism assessed using the Health and Work Performance Questionnaire Short Form (HPQ-SF).
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering the three consecutive hottest months and four alternate months.
Indoor air temperature
Indoor air temperature (℃) measured using Hobo MX1101 heat and humidity measurement device.
Time frame: Measurements at 15 minute intervals for 12 months.
Indoor relative humidity
Ratio of the amount of water vapor present in the air to the greatest amount possible at the same temperature (%) measured using Hobo MX1101 heat and humidity measurement device.
Time frame: Measurements at 15 minute intervals for 12 months.
Indoor heat index
Index that combines air temperature and relative humidity (℃) based on temperature and humidity measurements from the Hobo MX1101 heat and humidity measurement device calculated using the formulae endorsed by the US National Oceanic and Atmospheric Administration.
Time frame: Measurements at 15 minute intervals for 12 months.
Household energy expenditure
Self-reported household energy expenditure assessed using a recall questionnaire from the head of the household.
Time frame: Eight measurements will be taken: one at baseline and seven over 12 months, covering the three consecutive hottest months and four alternate months.
Plan to share: Yes — Data that can be shared unconditionally underpinning the published research articles will be made available to other researchers at the time of publication, and data will be linked via the article DOI. Data that cannot be unconditionally shared upon publication owing to confidentiality or data protection requirements will be identified as such and a contact email will be provided in relevant publications for data access enquiries by other researchers. Individual names of study participants and identifying factors will be removed prior to data sharing. It is expected that demographic data of people at the study sites (family size and composition, basic socioeconomic indicators) may contain personally identifiable information and location data. All such data will be removed prior to storage on online data repositories and therefore will be available to be publicly shared at the time of publication of manuscripts.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report
Time frame: At the time of publication.
Data sharing details ↗ · reflect.org.nz
No publications or documents are linked to this record.
Start is estimated for May 2026; primary completion for Sep 2027, 15 months later.
Of 3,468 non-industry interventional studies with no phase under Depression, half reached primary completion within 21 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 41. This study's planned 15 months is below that.
Counting every sponsor, half of 3,566 studies reached it within 21 months; a quarter within 9 and three quarters within 41.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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