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Trial registered on ANZCTR


Registration number
ACTRN12609000610235
Ethics application status
Approved
Date submitted
20/07/2009
Date registered
22/07/2009
Date last updated
3/12/2013
Type of registration
Retrospectively registered

Titles & IDs
Public title
Health and Unflued Gas Heaters Study: The Impact of Unflued Low NOx Gas Heaters on Lung Function and Respiratory Symptoms in Schoolchildren.
Scientific title
In schoolchildren aged 8 to 12 years, is exposure to unflued low NOx gas heaters, compared to flued gas heaters, associated with worse lung function and more frequent respiratory symptoms?
Universal Trial Number (UTN)
Trial acronym
HUGHS
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Respiratory Health 237295 0
Asthma 237296 0
Condition category
Condition code
Respiratory 239620 239620 0 0
Asthma

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Low NOx unflued gas heaters
The exposure period is schooldays each week (Monday to Friday). The washout period between exposures is the weekend (Saturday and Sunday).
The low NOx unflued gas heaters will be used in alternating weeks during the 6 week exposure assessment. The low NOx unflued gas heaters will be used for a total of 3 weeks and the flued gas heaters will be used for a total of 3 weeks. The classroom teacher will not know which type of heater is the exposure heater for the week. The classroom teacher will make decisions about the need for heating in the classroom. This will be in line with their usual practice.
Intervention code [1] 236974 0
Other interventions
Comparator / control treatment
Flued vs unflued low NOx gas heaters

The flued gas heater has a vent to the outside and emissions from the heater are vented to the outside. The low NOx unflued gas heater does not have a vent.

The flued gas heaters will be used in alternating weeks during the 6 week exposure assessment. The low NOx unflued gas heaters will be used for a total of 3 weeks and the flued gas heaters will be used for a total of 3 weeks. The classroom teacher will not know which type of heater is the exposure heater for the week. The classroom teacher will make decisions about the need for heating in the classroom. This will be in line with their usual practice.
Control group
Active

Outcomes
Primary outcome [1] 238406 0
Forced Expiratory Volume in 1 second (FEV1)

Forced Expiratory Volume in 1 second (FEV1) will be assessed by Mini-Wright Digital Peak Flow Meter (Clement Clarke International). Children will record three FEV1 manoeuvres each morning and each night during the 6 week exposure assessment period. The Mini-Wright Digital will electronically store with date and time stamp all FEV1 manoeuvres.
Timepoint [1] 238406 0
average over one week periods
Secondary outcome [1] 244881 0
exhaled nitric oxide

The test is performed by having the child breath room air in through a scrubber, designed to remove nitric oxide from ambient air. The child will stand, with a nose clip on and inhale and exhale three times through the scrubber then immediately after the third inhalation the subject will exhale through a rotameter. The rotameter incorporates a flow sensor and the subject will be instructed to maintain the expiratory flow rate at about 200 mls per second, by keeping a floating ball between two sets of flow rate markers. The device will also incorporate a manually operated valve. Initially, the valve is set to be open to the room allowing the technician to discard the dead space volume. After approximately one to two seconds of expiration, the technician turns the valve to direct the airflow into a 3L impermeable polyethylene (Scholle Industries, Adelaide, Australia) collecting bag. The subject is instructed to continue to exhale down to near residual volume. This procedure will be repeated up to two or three times until approximately 1L was collected into the bag. Within 6 hours of collection, the contents of the impermeable polyethylene bag will be aspirated into a chemiluminescent analyser (Model 42C; Thermo Environmental Instruments, Franklin, MA) to measure nitric oxide (NO) concentration in parts per billion (ppb).
Timepoint [1] 244881 0
at the end of each one week period
Secondary outcome [2] 244882 0
respiratory symptoms
Symptoms include Cough, Wheeze or Chest tightness, Fever, Sore throat, Runny or blocked nose, Soreness of teeth or gums, Eye irritation, Stomach ache
Children will record symptoms each morning and each night in a paper diary during the 6 week exposure assessment period.
Timepoint [2] 244882 0
over the one week period

Eligibility
Key inclusion criteria
Classrooms: 1) in Blue Mountains or Southern Highlands region of NSW
2) heated by low NOx unflued gas heaters
3) no artificial ventilation or other heating sources
4) suitable for installation of flued gas heater
5) Year 3 to Year 6 students
Students: all students within these classes are eligible
Minimum age
8 Years
Maximum age
12 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Classrooms: 1) artificial ventilation or other heating source
2) unsuitable for installation of flued gas heater
Students: those who, in the opinion of the class teacher, would not be able to undertake the procedures outline below due to physical or intellectual disability or due to inability to communicate in English.

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
This is a cluster-randomised cross-over study all participants will receive both conditions.
During a six week period in the winter months either the low NOx unflued gas heater or the flued gas heater will be in active mode for one week periods. These periods will be arranged in three consecutive pairs. For each classroom, the order of operation of the unflued and flued gas heaters will be randomised separately for each pair of weeks. Hence, each classroom will be using a low NOx unflued gas heater for three one week periods and a flued gas heater for three one week periods. During this time the heaters will be operated at the discretion of the class teacher, in the usual way, according to heating need. The class teacher and the students within the classes will not be aware which of the heaters is in active mode, that is, they will be blinded to the exposure.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
We will used a computer generated randomisation for the first of each pair of weeks for each class.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Safety
Statistical methods / analysis

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 1951 0
2780
Recruitment postcode(s) [2] 1952 0
2575

Funding & Sponsors
Funding source category [1] 237356 0
Other
Name [1] 237356 0
NSW Department of Education and Training
Country [1] 237356 0
Australia
Primary sponsor type
Other
Name
NSW Department of Education and Training
Address
GPO Box 33, Sydney NSW 2001
Australia
Country
Australia
Secondary sponsor category [1] 236849 0
None
Name [1] 236849 0
Address [1] 236849 0
Country [1] 236849 0
Other collaborator category [1] 772 0
Other
Name [1] 772 0
NSW Department of Health
Address [1] 772 0
Locked Mail Bag 961
North Sydney NSW 2059
Australia
Country [1] 772 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 239485 0
University of Sydney Human Research Ethics Committee
Ethics committee address [1] 239485 0
Ethics committee country [1] 239485 0
Australia
Date submitted for ethics approval [1] 239485 0
Approval date [1] 239485 0
07/04/2009
Ethics approval number [1] 239485 0
04-2009/11667

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 29927 0
Address 29927 0
Country 29927 0
Phone 29927 0
Fax 29927 0
Email 29927 0
Contact person for public queries
Name 13174 0
Wafaa Ezz
Address 13174 0
Box M77 Missenden Road Post Office
Camperdown, NSW, 2050
Country 13174 0
Australia
Phone 13174 0
+61 2 91140455
Fax 13174 0
+61 2 91140014
Email 13174 0
wafaaezz@woolcock.org.au
Contact person for scientific queries
Name 4102 0
Wafaa Ezz
Address 4102 0
Box M77 Missenden Road Post Office
Camperdown, NSW, 2050
Country 4102 0
Australia
Phone 4102 0
+61 2 91140455
Fax 4102 0
+61 2 91140014
Email 4102 0
wafaaezz@woolcock.org.au

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What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

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