1.Emergency Department demand associated with seasonal influenza, 2010 through 2014, New South Wales, Australia
David Muscatello ; Kendall Bein ; Michael Dinh
Western Pacific Surveillance and Response 2017;8(3):11-20
Introduction: Influenza’s impact on health and health care is underestimated by influenza diagnoses recorded in health-care databases. We aimed to estimate total and non-admitted influenza-attributable hospital Emergency Department (ED) demand in New South Wales (NSW), Australia.
Methods: We used generalized additive time series models to estimate the association between weekly counts of laboratory-confirmed influenza infections and weekly rates of total and non-admitted respiratory, infection, cardiovascular and all-cause ED visits in NSW, Australia for the period 2010 through 2014. Visit categories were based on the coded ED diagnosis or the free-text presenting problem if no diagnosis was recorded.
Results: The estimated all-age, annual influenza-attributable respiratory, infection, cardiovascular and all-cause visit rates/100 000 population/year were, respectively, 120.6 (99.9% confidence interval [CI] 102.3 to 138.8), 79.7 (99.9% CI: 70.6 to 88.9), 14.0 (99.9% CI: 6.8 to 21.3) and 309.0 (99.9% CI: 208.0 to 410.1). Among respiratory visits, influenza-attributable rates were highest among < 5-year-olds and ≥ 85-year-olds. For infection and all-cause visits, rates were highest among children; cardiovascular rates did not vary significantly by age. Annual rates varied substantially by year and age group, and statistically significant associations were absent in several years or age groups. Of the respiratory visits, 73.4% did not require admission. The non-admitted proportion was higher for the other clinical categories. Around 1 in 100 total visits and more than 1 in 10 respiratory or infection visits were associated with influenza.
Discussion: Influenza is associated with a substantial and annually varying burden of hospital-attended illness in NSW.
2.Impact of seasonal influenza on polyclinic attendances for upper respiratory tract infections in Singapore
Annabel C.Y. Soh ; Anurag Sharma ; David J. Muscatello
Western Pacific Surveillance and Response 2020;11(2):27-36
Purpose:
The burden of influenza on primary healthcare services is not well-established in tropical countries where there are no clearly defined influenza seasons. We aimed to estimate the association between influenza infection activity and polyclinic attendance rates for upper respiratory tract infections (URTI) in the Singapore population.
Methods:
We used generalized additive time series models to estimate the association between the proportion of respiratory tests positive for influenza infection in Singapore reported to the World Health Organization every week, and the population rate of polyclinic attendances in Singapore for physician-diagnosed URTI, which includes influenza-like illness (ILI), for a total of 6 years from 2012 through 2017. Where data were available, we controlled for other infections that can cause fever or respiratory symptoms.
Results:
Influenza, dengue fever and chickenpox (varicella) were positively associated with acute URTI polyclinic attendances. The estimated URTI polyclinic attendance rates attributable to influenza, dengue fever and chickenpox were 618.9 (95% confidence interval [CI] 501.6, 736.3), 153.3 (95% CI 16.5, 290.2) and 1751.5 (95% CI: 1246.3, 2256.8) per 100,000 population per year, respectively.
Conclusions
Influenza poses a considerable burden on primary healthcare services in Singapore. However, a substantial number of polyclinic attendances due to febrile infections such as dengue fever and chickenpox appear to be recorded as URTI in the polyclinic database. These associations require further investigation.
3.Monitoring mortality in the setting of COVID-19 pandemic control in Victoria, Australia: a time series analysis of population data
Lalitha Sundaresan ; Sheena G Sullivan ; David J Muscatello ; Daneeta Hennessy ; Stacey L Rowe
Western Pacific Surveillance and Response 2025;16(1):29-39
Objective: Mortality surveillance was established in the state of Victoria just before the COVID-19 pandemic. Here, we describe the establishment of this surveillance system, justify the modelling approach selected, and provide examples of how the interpretation of changes in mortality rates during the pandemic was influenced by the model chosen.
Methods: Registered deaths occurring in Victoria from 1 January 2015 to 31 December 2020 were sourced from the Victoria Death Index. Observed mortality rates were compared to a raw historical 5-year mean and to predicted means estimated from a seasonal robust regression. Differences between the observed mortality rate and the historical mean (delta-MR) and excess mortality rate from the observed and predicted rates were assessed.
Results: There were 20 375 COVID-19 cases notified in Victoria as of 31 December 2020, of whom 748 (3.7%) died. Victorians aged >=85 years experienced the highest case fatality ratio (34%). Mean observed mortality rates in 2020 (MR: 11.6; 95% confidence interval [CI]: 11.4, 11.9) were slightly reduced when compared with the annual rate expected using the historical mean method (mean MR: 12.2; 95% CI: 12.1, 12.3; delta-MR: -0.57; 95% CI: -0.77, -0.38), but not from the rate expected using the robust regression (estimated MR: 11.7; 95% prediction interval [PI]: 11.5, 11.9; EMR: -0.05; 95% CI: -0.26, 0.16). The two methods yielded opposing interpretations for some causes, including cardiovascular and cancer mortality.
Discussion: Interpretation of how pandemic restrictions impacted mortality in Victoria in 2020 is influenced by the method of estimation. Time-series approaches are preferential because they account for population trends in mortality over time.
4.Emergency medical teams in WHO’s Western Pacific Region
Sean T Casey ; Erin Elizabeth Noste ; Anthony T Cook ; David Muscatello ; David James Heslop
Western Pacific Surveillance and Response 2023;14(6):61-77
This regional analysis aims to provide a comprehensive review of emergency medical team development and action in health emergency response in the Western Pacific Region from 2010 to 2024. It details national, subregional and regional efforts to strengthen health emergency preparedness, response and resilience; it notes challenges faced by the teams in these efforts; and it provides examples that could be adopted or adapted to strengthen their development and action around the world. Emergency medical teams are critical components of national, regional and global health emergency workforces, enabling rapid, high-quality and self-sufficient responses to health emergencies domestically or internationally. They comprise clinical, mental health, public health, logistics and water/sanitation/hygiene personnel who collaborate in providing critical services to affected populations during health emergencies. By the end of 2024, emergency medical teams had been established in nearly every country in the Western Pacific Region, with 16 classified for international deployments, and many national teams developed to strengthen response to domestic emergencies. This analysis is based on published peer-reviewed literature on emergency medical team development and action in health emergencies in the Western Pacific Region, as well as publicly available data on team collaboration and deployment for health emergency response. This analysis considers the global evolution of the World Health Organization Emergency Medical Team Initiative and describes its development in the Western Pacific Region, including how the teams have contributed to emergency response efforts, and the key enabling factors and challenges faced as they develop and respond to emergencies. The analysis concludes by highlighting opportunities for future development, collaboration, research and insights that may be applicable to the global development of emergency medical teams.