A study of the effectiveness of the Air Quality Health Index (AQHI) in reducing harmful effects of air pollution on the heart and lungs in adults 55 and over

ISRCTN ISRCTN26552763
DOI https://doi.org/10.1186/ISRCTN26552763
Secondary identifying numbers 810438
Submission date
05/05/2015
Registration date
07/05/2015
Last edited
13/12/2019
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Signs and Symptoms
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
Air pollution can seriously affect people’s health; young children and older adults are particularly vulnerable to its effects. Air pollution, which mainly comes from traffic exhaust fumes, can cause breathing and heart problems and has been linked to disease and early death. Older adults are encouraged to be physically active and carry out daily activities such as walking, cycling and taking part in sports to maintain their health. However, many physical activities are performed outdoors. Normally, outdoor activities are a healthy way to keep fit, but when air pollution levels are high, outdoor exercise may have a negative effect on a person’s health. The Air Quality Health Index (AQHI) is a health risk communication tool which provides information on current and forecast air quality conditions. The AQHI tool provides advice to guide outdoor activities and to reduce the risk of adverse health effects from exposure to high levels of air pollution. This study aims to test whether following AQHI advice is effective in reducing the risk of adverse health effects of air pollution in healthy older adults.

Who can participate?
Healthy adults 55 years and older.

What does the study involve?
Participants are randomly allocated into one of two groups. Those in group 1 (intervention group) are asked to exercise every day, but to exercise indoors rather than outdoors when the forecast AQHI value is 5 or greater. Those in group 2 (control group) are asked to exercise outdoors daily. All participants complete 10 weeks of daily health measures before and after exercise at home. Health measures are also carried out every week at a central site for the duration of the study.

What are the possible benefits and risks of participating?
Participants will not benefit directly from participating in this study; however there is financial compensation at the completion of data collection. This study will entail a moderate time commitment of approximately 1 ½ hours per day and 4 hours once per week for 10 weeks. Clinical tests may cause some discomfort, however, any discomfort should be brief and transient. Some participants may experience some skin irritation at the electrode sites, but this reaction will disappear.

Where is the study run from?
University of Western Ontario (Canada)

When is the study starting and how long is it expected to run for?
Feb 2015 to August 2016

Who is funding the study?
Health Canada (Canada)

Who is the main contact?
Dr D Stieb
dave.stieb@hc-sc.gc.ca

Contact information

Dr David Stieb
Public

445-757 West Hastings St. - Federal Tower
Vancouver
V6C 1A1
Canada

Phone 604 666 3701
Email dave.stieb@hc-sc.gc.ca

Study information

Study designSingle-centre randomised trial
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Community
Study typePrevention
Participant information sheet Not available in web format, please use contact details to request a participant information sheet
Scientific titleA randomised controlled trial of the effectiveness of the Air Quality Health Index (AQHI) in reducing cardiac and respiratory adverse effects of air pollution in adults 55 and over
Study objectivesReducing outdoor physical activity in accordance with advice provided through the Air Quality Health Index will reduce adverse cardiac and respiratory effects of air pollution in adults 55 and over.
Ethics approval(s)Health Canada/Public Health Agency of Canada, 23/04/2015, ref: 2012-0035.
Health condition(s) or problem(s) studiedCardiac and respiratory health
Intervention1. The intervention group will be asked to exercise indoors rather than outdoors and avoid other outdoor activity prior to physiological testing when the maximum AQHI is forecast to be 5 or higher (on the remaining days they will exercise outdoors). The intervention group will receive instructions for a simple indoor exercise routine that can be completed on designated days.
2. The control group will exercise outdoors daily
Intervention typeBehavioural
Primary outcome measureWeekly measures before and after 30 minutes of mild activity:
1. Heart rate variability (Holter monitoring)
2. Endothelial function (Reactive Hyperemia Index - Peripheral artery tone)
3. Oxygen saturation (finger oximeter)
4. Blood pressure (automated sphygmomanometer)
5. Fraction of exhaled Nitric Oxide (exhaled NO sensor)
6. Spirometric measures (spirometer)
7. Urinary oxidative stress markers (vascular endothelial growth factor (VEGF), 8-isoprostane, malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG))
Secondary outcome measuresRespiratory symptoms.
Overall study start date01/02/2015
Completion date31/08/2016

Eligibility

Participant type(s)Healthy volunteer
Age groupSenior
SexBoth
Target number of participants80
Total final enrolment72
Key inclusion criteria1. Participants must be 55 years of age or older
2. Non-smokers
3. Not exposed to environmental tobacco smoke at home
4. No seasonal allergies
Key exclusion criteria1. Unstable angina
2. Atrial flutter
3. Atrial fibrillation
4. Paced rhythm
5. Left bundle branch block
6. Implanted cardioverter-defibrillator (ICD)
7. Participants with allergies to latex or adhesives will be excluded
Date of first enrolment18/05/2015
Date of final enrolment30/06/2015

Locations

Countries of recruitment

  • Canada

Study participating centre

University of Western Ontario
1151 Richmond St
London
N6A 3K7
Canada

Sponsor information

Health Canada
Government

50 Colombine Drwy
Tunney's Pasture
Ottawa
K1A 0K9
Canada

ROR logo "ROR" https://ror.org/05p8nb362

Funders

Funder type

Government

Health Canada
Government organisation / National government
Alternative name(s)
Santé Canada
Location
Canada

Results and Publications

Intention to publish date31/12/2018
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot expected to be made available
Publication and dissemination planPapers will be submitted to peer reviewed journals regarding primary study findings and possibly secondary findings regarding effect modification by genotype. It is estimated that the first paper will be submitted by 31/12/2018.
IPD sharing planThe datasets generated during and/or analysed during the current study are not expected to be made available due to privacy restrictions.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article results 12/12/2019 13/12/2019 Yes No

Editorial Notes

13/12/2019: Publication reference and total final enrolment number added.
15/02/2018: Publication and dissemination plan updated, IPD sharing statement added.