Mechanical Heat Recovery Ventilation on House Dust Mite Sensitive Asthma

December 23, 2009 updated by: University of Glasgow

Randomised Controlled Trial of Mechanical Heat Recovery Ventilation on Asthma Control of Patients Allergic to the House Dust Mite

Asthma has become increasingly common in the UK, demanding our consideration of the cause. Many patients with asthma are allergic to house dust mites, which thrive in modern housing. Improving ventilation in the home has been shown to reduce dust mite levels, by reducing humidity levels. It is hoped that, by removing the dust mites from homes, asthma may improve. In this study, 140 volunteers will have their carpets steam-cleaned and new allergy bedding provided, before a team of architects installs a ventilation system in the loft. Half of the units will be switched on at the beginning of the study. The other half will be switched on in 12 months time, but only the architects know which units are active. The medical team will compare the asthma, and measures of inflammation in the airways, over that year.

It is due for completion in April 2007.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The prevalence of asthma is rising sharply in the UK. The house dust mite is the most common trigger associated with asthma, thriving in the humid microclimate favoured by modern housing. Could this be redressed by investment in improved ventilation in local housing? In a pilot study in North Lanarkshire Council housing stock, we demonstrated that dust mite avoidance, in combination with installation of domestic mechanical heat recovery ventilation (MHRV), could inhibit the re-colonisation of house dust mites by reduction of indoor air humidity. In this second phase, a double blind randomized placebo- controlled trial will test the resultant effect on asthma. It will be complete in November 2006. 140 patients with asthma and house dust mite allergy are being recruited and all will have new bedding, mattress covers and carpets cleaned. All will have MHRV units installed in their home, but only half will be activated, before 12 months of environmental and clinical monitoring. The primary endpoint is morning peak flow rate. Secondary endpoints include symptom scores, spirometry, rates of exacerbations, quality-of-life, and economic evaluations. Demonstration that well ventilated, energy efficient dwellings improve the respiratory health of patients with allergic asthma could be of considerable importance in helping the NHS cope with the commonest chronic disease in Scotland.

Study Type

Interventional

Enrollment (Actual)

119

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
      • North Lanarkshire, United Kingdom
        • Monklands General Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

16 years to 60 years (ADULT, CHILD)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • House dust mite sensitive
  • FEV1 greater than 50%
  • Symptomatic asthma or 12% reversibility on spirometry or 15%PEFR lability

Exclusion Criteria:

  • Multi-storey flat

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: TREATMENT
  • Allocation: RANDOMIZED
  • Interventional Model: PARALLEL
  • Masking: QUADRUPLE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
PLACEBO_COMPARATOR: 1
Mechanical heat recovery ventilation units installed but not fully functional
Device: Mechanical Heat Recovery Ventilation
De-humidification without loss of heat
Other Names:
  • Ventaxia
ACTIVE_COMPARATOR: 2
Mechanical heat recovery ventilation unit installed and active
Device: Mechanical Heat Recovery Ventilation
De-humidification without loss of heat
Other Names:
  • Ventaxia

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
morning Peak Flow
Time Frame: 1 year
1 year

Secondary Outcome Measures

Outcome Measure
Time Frame
quality of life
Time Frame: 1 year
1 year
symptom scores
Time Frame: 1 year
1 year
exacerbation rates
Time Frame: 1 year
1 year
spirometry
Time Frame: 1 year
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Glasgow

Collaborators

Chief Scientist Office of the Scottish Government
North Lanarkshire Council
South Lanarkshire Council
North Glasgow Primary Care Trust
Vent-axia Ltd
Scottish Power
Energy Action Scotland
Communities Scotland

Investigators

  • Principal Investigator: Prof Neil C Thomson, MD FRCP, The University of Glasgow

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 1, 2003

Study Completion (ACTUAL)

April 1, 2007

Study Registration Dates

First Submitted

September 2, 2005

First Submitted That Met QC Criteria

September 2, 2005

First Posted (ESTIMATE)

September 7, 2005

Study Record Updates

Last Update Posted (ESTIMATE)

December 24, 2009

Last Update Submitted That Met QC Criteria

December 23, 2009

Last Verified

November 1, 2007

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CZB/4/47
  • CSO CZB/4/47 and BO/01/69

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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