Clinical trial NCT00437541: Housing, Insulation and Health Study
Official title: The Impact of Insulating Domestic Houses on the Health of Occupants: an Intervention Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Respiratory Illness
Asthma
Keywords: Insulation
Warmth
Humidity
Damp
Cold
Respiratory
Mould
Lead sponsor: University of Otago
Sponsor class: OTHER
First posted: 2007-02-21
Enrollment: 4000
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: In six communities we will seek out households where someone who has a history of respiratory problems. For the first winter we will measure temperature and humidity of the house and health of occupants. We will insulate half the houses and the next winter compare them with the uninsulated houses to see if warmer houses improve health.

Detailed description: Damp, cold indoor environments are bad for the health of people who live in them, particularly if they have respiratory problems or are vulnerable, such as the young or the very old. This is a community based study designed to test the hypothesis that insulating domestic houses will make them warmer and that this increase in indoor temperature will improve their health and wellbeing.

Following two pilot studies, the first among older people in city council flats and the second among home owners in Waitara. We have followed the "Waitara model" where community networks will be mobilised to identify households in each community where there is someone with a on going respiratory problem. Seven communities have been selected to help test these hypotheses and have agreed to participate Otara, Gisborne, Mahia/Nuhaka, Taranaki, Porirua, West Coast and Christchurch. Low income areas with high Maori populations have been deliberately selected to maximise the potential health gains.

Two hundred houses in each community will be insulated free of charge to the occupants. The workers who will insulate the homes will be local people employed through the Department of Work and Income (WINZ).

Once the houesholds are selected they will be randomly assigned to intervention or control groups. During the first winter, all 1400 households will be monitored for temperature and humidity and their comfort, health and healthcare utilization will be recorded. Half the households, assigned to the intervention group, will be fully insulated during the spring. The following winter, all the initial measurements taken from both the intervention and control group will be repeated. At the end of the study period, all control houses will be insulated.

This study has developed from a natural intervention being carried out by the Energy Efficiency Conservation Authority (EECA) to insulate domestic houses in New Zealand and is a major collaborative effort, which will shed light on the effectiveness of insulation in improving health and wellbeing. The impact of housing refurbishment on health has not previously been examined. There is considerable government and policy interest in promoting healthy housing and there is strong community interest in ensuring the housing stock is improved in order to lower health risks.

Eligibility criteria: Inclusion Criteria:

* Live in Study area
* At least one person in the household must had had respiratory illness within the last year, well members of the same household may also participate
* house currently uninsulated
* interested in taking part in research

Exclusion Criteria:

* Intending to move within study period

Primary outcomes:
measure: Self reported general health, During the first winter post intervention
measure: Indoor temperature and relative humidity, During the first winter post intervention
Secondary outcomes:
measure: Energy consumption, During the first winter post intervention
measure: Wheezing, During the first winter post intervention
measure: Days off school and work, During the first winter post intervention
measure: GP visits, During the first winter post intervention
measure: Inpatient hospital admissions, During the first winter post intervention
Other outcomes:
Locations:
city: Otara
country: New Zealand
facility: Otara Health Inc
state: Auckland
city: Mahia/Nuhaka
country: New Zealand
facility: Te Iwi O Rakaipaaka
state: East Coast
city: Mahia/Nuhaka
country: New Zealand
facility: Te Wahine O Kahungungu
state: East Coast
city: Opotiki
country: New Zealand
facility: Opotiki Trade Training
state: Gisborne
city: New Plymouth
country: New Zealand
facility: Te Puni Kokiri
state: Taranaki
city: Porirua
country: New Zealand
facility: Porirua Housing Action Group
state: Wellington
city: Rata - Hokitika
country: New Zealand
facility: Maori Womans Welfare League
state: West Coast
city: Christchurch
country: New Zealand
facility: Crown Public Health
Study officials:
affiliation: University of Otago
name: Philippa L Howden-Chapman, PhD
role: STUDY_DIRECTOR
affiliation: University of Otago
name: Julian Crane, FRCP
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Otago
name: Michael G Baker, FRACMA
role: PRINCIPAL_INVESTIGATOR
affiliation: Massey University
name: Chris Cunningham, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: CRESA
name: Kay Saville-Smith, MA Hons
role: PRINCIPAL_INVESTIGATOR
affiliation: Landcare Research Limited
name: Nick Waipara, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Otago
name: Alistair Woodward, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Otago
name: Des O'Dea, BSc Hons
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Otago
name: Tony Blakely, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Otago
name: Cheryl Brunton, FAFPHM
role: PRINCIPAL_INVESTIGATOR
References:
citation: Howden-Chapman P, Crane J, Matheson A, Viggers H, Cunningham M, Blakely T, O'Dea D, Cunningham C, Woodward A, Saville-Smith K, Baker M, Waipara N. Retrofitting houses with insulation to reduce health inequalities: aims and methods of a clustered, randomised community-based trial. Soc Sci Med. 2005 Dec;61(12):2600-10. doi: 10.1016/j.socscimed.2005.04.049. Epub 2005 Aug 2.