Assessing the Effects of Cool Roofs on Indoor Environments and Health in Niue

NCT06570993 | Completed DMC

• 2 other identifiers: 3728160226745/Z/22/Z
• Study Type: interventional
• Target: 288
• Locations: 1 country
• Sites: 1

Brief Summary

Ambient air temperatures in the Pacific 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 in the Pacific 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 Niue. 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 Niue.

Conditions

Household Energy Expenditure; Resting Heart Rate; 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; Healthcare Provider Utilization; Hospitalization; Systolic Blood Pressure; Diastolic Blood Pressure; Inner Ear Canal Temperature; Dehydration; Sleep Quality; Cognition; Productivity; Aggression; Indoor Air Temperature; Indoor Relative Humidity; Indoor Heat Index

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).

  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)

Intervention

EXPERIMENTAL

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

Other: Cool roof

Control

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 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.

Intervention

Eligibility Criteria

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

You may qualify if:

• Participant criteria:
• Consenting adults aged 18 years and over.
• Expected to be available to participate in the study for at least nine months in the next 12 months.
• Household criteria:
• House has a metal roof.
• House is single-story.

You may not qualify if:

• Household criteria:
• Unstable house structure that does not permit the application of cool roof materials.
• Inaccessible by the research team.
• Significant roof damage defined as any penetrative roof defect that results in a hole in the roof OR over 25% of the roof rusted.

Sponsors & Collaborators

• London School of Hygiene and Tropical Medicine: collaborator
• Boston University: collaborator
• Secretaría de Educación Pública, México: collaborator
• University of Ouagadougou, Burkina Faso: collaborator
• Indian Institute of Public Health, India: collaborator
• Labfront: collaborator
• CogniFit Limited: collaborator
• Resene: collaborator
• Pacific Community: collaborator
• Habitat for Humanity: collaborator
• The Tindall Foundation: collaborator
• Aditi Bunker: lead
• Heidelberg University: collaborator
• Rutgers University: collaborator

Study Sites (1)

University of Auckland

Auckland, Niue

Location

Related Links

• Related Info

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

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 22, 2024
• First Posted: August 26, 2024
• Study Start: September 4, 2024
• Primary Completion: January 31, 2026
• Study Completion: January 31, 2026
• 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

NI (1)