Assessing the Effects of Cool Roofs on Indoor Environments and Health

NCT06579950 | Recruiting DMC

• 2 other identifiers: 3728162226745/Z/22/Z
• Study Type: interventional
• Target: 3,200
• Locations: 5 countries
• Sites: 5

Brief Summary

Ambient air temperatures in Asian, Latin American, African, and Pacific climate hotspots have broken record highs in 2024, driven by man-made climate change. Solutions are needed to reduce heat exposure in communities. Sunlight-reflecting cool roof coatings 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 especially vulnerable to increased indoor heat exposure. Heat exposure can instigate and worsen numerous physical, mental and social health conditions. The worst adverse health effects are being experienced in communities least able to adapt to heat exposure. By reducing indoor temperatures, cool roof use can promote physical, mental and social wellbeing in occupants. The long-term research goal is to identify viable passive housing adaptation technologies with proven health and environmental benefits to reduce the burden of heat stress in communities affected by heat globally. 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 five urban climate hotspots: Ouagadougou, Burkina Faso; Colima, Mexico; Ahmedabad, India; Niue; and Tavua, Fiji.

Conditions

Resting Heart Rate; Healthcare Provider Utilization; Hospitalization; Systolic Blood Pressure; Sleep Quality; Productivity; Aggression; Indoor Air Temperature; Blood Glucose Control; Depression; Heat-related Symptoms; Physician Diagnosed Heat-related Illnesses; Food Insecurity; Diet Quality; Health-related Quality of Life; Indoor Thermal Comfort; Coping Ability; Life Satisfaction; Diastolic Blood Pressure; Inner Ear Canal Temperature; Dehydration; Cognition; Indoor Relative Humidity; Indoor Heat Index; Household Energy Expenditure

Keywords

Hot Temperature; Humidity; Housing; Heart rate; Cardiovascular; Depression; Mental health; Blood glucose; Diabetes; Cool roof; Heat Stress

Outcome Measures

Primary Outcomes (3)

• 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 Blip portable automated sphygmomanometers.

  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.

  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.

  Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.

Secondary Outcomes (22)

• Heat-related symptoms

  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

  Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.

• Food insecurity

  Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.

• Diet quality

  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

  Eight measurements will be taken: one at baseline and seven over 12 months, covering three consecutive hottest months and four alternate months.

Study Arms (2)

Cool roof

EXPERIMENTAL

Households will receive sunlight reflecting 'cool roof' coating on their roofs.

Other: Cool roof

No cool roof

NO INTERVENTION

No cool roof application. Households will keep their original roofing for the duration of the trial.

Interventions

Cool roof OTHER

Cool roofs are a sunlight reflecting roof coating that can reduce indoor temperature. Cool roofs have high solar reflectance (reflecting the ultraviolet and visible wavelengths of sunlight, reducing heat transfer to the surface of a roof) and high thermal emittance (radiating absorbed solar energy).

Cool roof

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Permanent household resident.

You may not qualify if:

• Roof damage, inaccessible or instability of roof adversely affecting cool roof coating application.
• Participant unable to provide written/verbal informed consent.

Sponsors & Collaborators

• Aditi Bunker: lead
• Sika Services AG: collaborator
• SOPREMA: collaborator
• Engineered Polymer Solutions (EPS B.V.): collaborator
• Resene: collaborator
• Pacific Community: collaborator
• Habitat for Humanity: collaborator
• The Tindall Foundation: collaborator
• Rutgers University: collaborator
• Boston University: collaborator
• London School of Hygiene and Tropical Medicine: collaborator
• Heidelberg University: collaborator
• University of Ouagadougou, Burkina Faso: collaborator
• Indian Institute of Public Health, India: collaborator
• Fiji National University: collaborator
• Universidad de Colima: collaborator

Study Sites (5)

University Joseph Ki-Zerbo

Ouagadougou, Burkina Faso

ACTIVE NOT RECRUITING

Fiji National University

Suva, Fiji

RECRUITING

Indian Institute of Public Health Gandhinagar

Ahmedabad, Gandhinagar, India

ACTIVE NOT RECRUITING

Instituto Tecnológico de Hermosillo

Hermosillo, Sanora, Mexico

NOT YET RECRUITING

Niue

Alofi, Niue

ACTIVE NOT RECRUITING

MeSH Terms

Conditions

Depression; Personal Satisfaction; Dehydration; Sleep Initiation and Maintenance Disorders; Aggression; Psychological Well-Being; Diabetes Mellitus; Heat Stress Disorders

Condition Hierarchy (Ancestors)

Behavioral Symptoms; Behavior; Water-Electrolyte Imbalance; Metabolic Diseases; Nutritional and Metabolic Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases; Mental Disorders; Aberrant Motor Behavior in Dementia; Social Behavior; Glucose Metabolism Disorders; Endocrine System Diseases; Wounds and Injuries

Study Officials

• Collin Tukuitonga, Sir. Dr.

  University of Auckland, New Zealand

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Aditi Bunker, Dr

CONTACT

+49 6221 565344; aditi.bunker@uni-heidelberg.de

Collin Tukuitonga, Sir. Dr.

CONTACT

+6493737599; collin.tukuitonga@auckland.ac.nz

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: 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.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Co-Principal Investigator

Study Record Dates

• First Submitted: August 28, 2024
• First Posted: August 30, 2024
• Study Start: September 4, 2024
• Primary Completion (Estimated): September 30, 2027
• Study Completion (Estimated): September 30, 2027
• Last Updated: February 27, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR
• Time Frame: At the time of publication.

Locations

BU (1); FI (1); IN (1); NI (1); ME (1)