Epidemiology Group

Role

The Epidemiology Group conducts research that describes the prevalence of respiratory disease, risk factors for the development or remission of respiratory disease, and investigates interventions to reduce the burden of asthma and other respiratory diseases. Members of the Group have skills in statistics and database management and these skills are provided to all groups within the Woolcock.

Research

Childhood Asthma Prevention Study (CAPS)
This is a randomised controlled trial of house dust mite avoidance and dietary interventions for the prevention of asthma, implemented from birth in a cohort at high risk for developing asthma. The study started recruiting in 1997 and the assessment of 516 participants at age five years was completed in 2005. We demonstrated that we could successfully reduce house dust mite allergen levels in children’s beds and also that we could alter the ratio of omega-3 to omega-6 long chain polyunsaturated fatty acids in children’s plasma. However, neither of these interventions had any beneficial effect on the prevalence of asthma or allergic disease at age five years. These findings were published during 2006.

During this year we have also conducted a number of other important analyses of the data from this CAPS cohort: examining the time course of atopy, eczema and asthma/rhinitis during early childhood; describing seasonal and climatic variation in house dust mite allergen levels; exploring changes in immunological profile during the first five years of life; assessing the impact of duration of breast feeding, other infant feeding practices, possession of cats and dogs, and levels of fatty acids in the blood and the diet on the incidence of allergic disease during early childhood; and describing the incidence of snoring in children with rhinitis. We expect manuscripts reporting this work will be published during 2007.

Also during 2006, we have continued to assess children in the CAPS cohort, this time around their 8th birthday. This work has been proceeding very well, with good participation rates. We expect to start analysing these new data in 2008.

CAPS has been jointly funded by the NHMRC and the CRC for Asthma and Airways.

Lane Cove Tunnel Air Quality and Respiratory Health Study
There is substantial public concern about traffic-related air pollution. The Lane Cove Tunnel, which was scheduled to open in December 2006, will remove traffic from surface roads resulting in a redistribution of existing traffic-related air pollution, in particular a reduction in air pollution adjacent to the main bypassed surface road. This provides an excellent opportunity to measure the impact of changes in air quality on respiratory health.

We are conducting a series of studies to:
a) map air quality in the affected area, before and after the tunnel opens
b) measure the change in respiratory symptoms and lung function in a cohort of adults and children in the affected area and relate this to changes in air quality
c) test the short-term effect of exposure to emissions from a ventilation stack

Baseline investigations have been undertaken during 2006 and follow-up investigations will be undertaken during 2007, after the tunnel opens.

The study is principally funded by the CRC for Asthma and Airways with additional funding from NSW Health and the Australian Department of Environment and Heritage.

Burden of Obstructive Lung Disease (BOLD) study
Chronic obstructive pulmonary disease is a common cause of disability, hospitalisation and death in older people. However, it is poorly recognised, particularly in its early stages, and therefore there are few data on the prevalence of this disease.

BOLD is an international study, using a standardised sampling, questionnaire and lung function testing protocol, designed to provide reliable data on the prevalence of COPD and the description of its management.

During 2006, we have been undertaking the BOLD study in the south-eastern suburbs of Sydney. By December, 600 people age 40 years and over will have had a comprehensive assessment of their respiratory health completed by our field team. The findings will be reported during 2007 and will contribute to the international comparative study described above.

The Sydney BOLD study was jointly funded by GlaxoSmithKline, AstraZeneca, Boehringer Ingelheim, Pfizer, and Air Liquide. In addition, data management and quality control was supported by the international coordinating centre in Portland, Oregon, USA.

With our interstate collaborators, we have now been successful in gaining NHMRC funding to extend the BOLD study to four other centres: Busselton, WA; the Kimberley, WA; Melbourne, Vic;
and Tasmania.

Tuberculosis research
Over the last four years, we have been collaborating with colleagues in conducting a number of studies describing the epidemiology of tuberculosis in New South Wales.

Migrants to Australia who have evidence of past (inactive) tuberculosis are required to sign a “Tuberculosis Undertaking” prior to migration and are subject to surveillance by State health authorities after arriving in Australia. Using linkage analysis, we have quantified the actual incidence of tuberculosis in this sub-group of migrants and compared it to the incidence in other migrants. Using these and other data we have evaluated the effectiveness of this scheme as a TB control program.

Once again using data linkage, we have described the relation between molecular and demographic epidemiology of tuberculosis in NSW. This work was undertaken in collaboration with Professor Lyn Gilbert at Westmead.
Finally, in collaboration with Professor Warwick Britton at the Centenary Institute, we have examined genetic risk factors for reactivation of tuberculosis in a cohort of refugees who were screened for tuberculosis infection at Liverpool Hospital in the 1980s and 1990s.

This work was mainly undertaken by Dr Linh Nguyen in studies for his PhD and was funded by Ausaid, NSW Health, Community Health and Tuberculosis Australia (CHATA) and the South Western Sydney Research Foundation.

PACE evaluation
The Physician Asthma Communication and Education (PACE) Australia program was originally developed by Noreen Clark and Michael Cabana, University of Michigan, USA. PACE provides primary health care doctors with evidence-based asthma management guidelines and better communication skills to help them to teach parents to manage their child’s asthma. The program differs from conventional continuing education programs for doctors in that it is theory based and focuses on changing specific aspects of doctors’ behaviours in interacting with patients rather than on solely providing clinical asthma information. Studies in the USA have shown that doctors’ participation in the PACE program improves patients’ asthma outcomes and carer satisfaction.
During 2004/2005, the PACE program was adapted for implementation in Australia with General Practitioners (GPs) and results from the study demonstrated the program’s acceptability and value in a feasibility study.

The project is being run from The University of Sydney, Department of General Practice at Westmead. During 2006 members of the Epidemiology group provided study design and analysis advice and also developed the randomisation software. Recruitment commenced during the second half of 2006 and the first GPs will receive the intervention during December.