Unique Method of Forecasting Flu Epidemics Was Useful in First Wave of COVID-19

Using several sources of data, researchers at Linköping University in Sweden developed a new method to predict influenza (flu) epidemics, according to a study published in Emerging Infectious Diseases.

The team explained that the goal of the data analysis was to help them better plan for the redistribution of resources during epidemics so that all patients can receive the highest quality of care.

The researchers specifically focused on respiratory tract infections in their analysis, comparing 3 large medical care regions—Stockholm, West Gothia, and Scania—during the period between January 2008 and February 2019. They then developed a method of analysis that could give accurate forecasts for flu seasons under stable conditions.

"Our method predicts influenza epidemics by using data from real episodes of care and consultations about influenza symptoms with the Swedish Healthcare Direct. The various sources of data are used to forecast different phases of an epidemic, which makes our study unique," said principal author Armin Spreco, MD, a researcher in the Department of Health, Medicine and Caring Sciences at Linköping University and a specialist in epidemiology and statistics at Region Östergötland, in a press release.

The researchers explained that by looking only at admissions or visits to primary care, it would be impossible to predict the peak of a flu epidemic. However, by including extra sources of data that precede the peak by several weeks, such as calls made by county residents to Swedish Healthcare Direct, they were able to forecast the peak.

Additionally, the researchers noted that forecasting becomes more unpredictable during periods of social unrest, as people’s behavior and movement becomes more erratic, causing infections to spread in unanticipated directions. This would make forecasts from stable social conditions inaccurate if applied to periods of social upheaval, according to the study.

The research team had begun its investigation into forecasting for different types of viral epidemics and pandemics in 2005 during the outbreak of the avian flu. Swedish legislation on this issue at the time decided that it was a social responsibility to make plans for such occurrences in order to provide for populations in the best possible manner.

"During the second decade of the new millennium, we started to prepare the information systems used in our medical care region, such that routine data can be used for this type of analysis. We have been able to use our experiences from working with skilled statisticians and technical experts at Region Östergötland and in this way ensure that other databases in Sweden have prepared for the analyses needed for emergency purposes," said lead author Toomas Timpka, MD, PhD, professor in the Department of Health, Medicine and Caring Sciences at Linköping University, and consulting physician in Region Östergötland, in a press release.

Spreco noted that the research he conducted over the past 10 years has been helpful in relation to planning during the coronavirus disease 2019 (COVID-19) pandemic. The method his research team developed for forecasting the flu epidemic was applied to several Swedish regions during the first wave of the COVID-19 pandemic, and it will be applied again upon the event of a second wave in Sweden.

REFERENCE

Predicting influenza epidemics. Linköping, Sweden: Linköping University; October 15, 2020. eurekalert.org/pub_releases/2020-10/lu-pie101520.php. Accessed October 28, 2020.