The annual flu season adds up to 17,000 more patients a year to NSW emergency departments, an increased demand for services that is pushing hospitals close to the edge, a new study reveals.

NSW emergency departments failed to meet length–of–stay targets during the winter flu seasons of 2010–14, with more patients waiting longer to be seen and increased numbers giving up on treatment, a study has found.

The study of 11 million presentations to 115 NSW hospitals during the five–year period looked at the relationship between weekly flu activity and the number of people who stayed longer than four hours (a national benchmark) at a hospital emergency department.

It also looked at the number of people who left the hospital before starting or completing their treatment.

He says the peak flu period is associated with annual peaks in patients exceeding the length of stay target and more patient walk–outs.

“More patients in the emergency department with influenza means more being admitted to hospital for further treatment,” he says.

“So it’s not just the emergency departments and influenza patients that are affected. The additional hospital stress affects all patients including those needing to be admitted, and that’s seen in more patients staying longer and more patients giving up waiting for treatment.”

In 2012, around 17,000 more patients a year in NSW stayed in the emergency department longer than the target time of up to 4 hours. Around 13,000 more patients gave up waiting for treatment, Dr Muscatello says.

“Our study shows that the flu season might add additional stress to hospitals that push them over the edge of being able to manage the demand for their services.”

“Flu season is unpredictable, it’s very hard to know in advance how bad it’s going to be and when it’s going to take off,” Dr Muscatello says. “That’s why it’s important for health service managers to pay attention to the data that’s available.”

Meanwhile, individuals can assist hospitals to cope during flu season by ensuring they get the flu shot.

“This study didn’t look at vaccination, but vaccination is the best way to prevent influenza and would be the best available way to reduce the impact on hospitals,” Dr Muscatello says.

“Risk groups are important and get the vaccine for free from their GP.

“But everyone would benefit from immunisation. It’s suitable for most people 6 months and older.”

The 2012 flu season was the worst for NSW hospitals in the years studied, while the 2010 flu season was a low activity year, following the 2009 “swine flu” pandemic.

The research published in the journal Emergency Medicine Australasia was co–authored by Associate Professor Michael Dinh and Dr Kendall Bein of Royal Prince Alfred Hospital and the University of Sydney.