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Mechanical Heat Recovery Ventilation on House Dust Mite Sensitive Asthma

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ClinicalTrials.gov Identifier: NCT00148096
Recruitment Status : Completed
First Posted : September 7, 2005
Last Update Posted : December 24, 2009
Information provided by:

Study Description
Brief Summary:

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.

Condition or disease Intervention/treatment Phase
Asthma Device: Mechanical Heat Recovery Ventilation Phase 2

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 Design

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 119 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Randomised Controlled Trial of Mechanical Heat Recovery Ventilation on Asthma Control of Patients Allergic to the House Dust Mite
Study Start Date : February 2003
Study Completion Date : April 2007

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Asthma
U.S. FDA Resources

Arms and Interventions

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 Name: Ventaxia
Active Comparator: 2
Mechanical heat recovery ventilation unit installed and active
Device: Mechanical Heat Recovery Ventilation
De-humidification without loss of heat
Other Name: Ventaxia

Outcome Measures

Primary Outcome Measures :
  1. morning Peak Flow [ Time Frame: 1 year ]

Secondary Outcome Measures :
  1. symptom scores [ Time Frame: 1 year ]
  2. exacerbation rates [ Time Frame: 1 year ]
  3. quality of life [ Time Frame: 1 year ]
  4. spirometry [ Time Frame: 1 year ]

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   16 Years to 60 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

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
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00148096

United Kingdom
Monklands General Hospital
North Lanarkshire, United Kingdom
Sponsors and Collaborators
University of Glasgow
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
Principal Investigator: Prof Neil C Thomson, MD FRCP The University of Glasgow
More Information

Additional Information:
ClinicalTrials.gov Identifier: NCT00148096     History of Changes
Other Study ID Numbers: CZB/4/47
CSO CZB/4/47 and BO/01/69
First Posted: September 7, 2005    Key Record Dates
Last Update Posted: December 24, 2009
Last Verified: November 2007

Keywords provided by University of Glasgow:
house dust mite

Additional relevant MeSH terms:
Bronchial Diseases
Respiratory Tract Diseases
Lung Diseases, Obstructive
Lung Diseases
Respiratory Hypersensitivity
Hypersensitivity, Immediate
Immune System Diseases