Seminar - Did emergency dept visits and admissions in Sydney increase during the 2009 dust storm?

16 May 2012

Full title: Did emergency department visits and hospital admissions in Sydney increase during the 2009 dust storm?

Presenter: Dr Alistair Merrifield, Research Fellow, School of Public Health

A large growing body of literature supports the association between exposure to particulate air pollution and adverse health outcomes. During September 2009, a rare large dust storm event was experienced in Sydney, NSW, Australia. Extremely high levels of respirable particles were recorded. We conducted an analysis to determine whether the dust storm was associated with increases in all-cause, cardiovascular, respiratory and asthma-related ED presentations and hospital admissions. We used statistical models to model the ED presentations and hospital admissions and adjust for pollutants, humidity, temperature and day of week effects to obtain estimates of relative risks (RR), 95% confidence intervals and p-values associated with the dust storm.
The dust storm period was associated with large significant increases in asthma ED visits (RR 1.33, 95% CI 1.23-1.44, p<0.001) and asthma hospital admissions (RR 1.14, 95% CI 1.03-1.27, p=0.012); and to a lesser extent, all ED visits (RR 1.10, 95% CI 1.09-1.11, p<0.01), all-cause hospital admissions (RR 1.04, 95% CI 1.03-1.05, p<0.01) and respiratory ED visits (RR 1.12, 95% CI 1.09-1.16, p<0.01). There was no significant increase in cardiovascular ED visits (p=0.97) or cardiovascular hospital admissions (p=0.30). Age-specific analyses showed the dust storm wasn't associated with increases in cardiovascular or respiratory ED visits in the 65+ year age group; the 5 years and younger group had higher risks of respiratory and asthma-related ED presentations. We recommend public health measures, especially targeting asthmatics, should be implemented during future dust storm events.

About the speaker: Alistair Merrifield is currently in the third year of the Biostatistical Officer Training program at NSW Health. He started his statistical life at Victoria University of Wellington in NZ, being involved in earthquake prediction. He came to the University of Sydney to complete a PhD in mathematical biology (group behaviour of animals, particularly honeybees). Since then, he has become more involved in medical related work. He has worked at Melbourne University on cell migrations in developing embryos, clinical trials at the NHMRC Clinical Trials Centre and on end stage kidney disease at the School of Public Health at the University of Sydney. This work was done during his placement in the Environmental Health Branch of NSW Health.

Hosted by The George Institute for International Health

Time: 11am

Location: 341 George Street, Level 6, training room 1 (Wynyard)

Contact: Serigne Lo

Phone: 02 9657 0329

Email: 3103393408111c31093319013e0c3b4d1901095438233663531d