More than 60 per cent of fake news read online about healthcare issues are considered credible, according to a major new study published by Kingston University (KU).

The research was carried out by leading health economists from KU and was commissioned by the Italian Government's Ministry of Health.

It involved around 1,900 people aged between 18 and 60.

The study was led by Professor Giampiero Favato and Dr Andrea Marcellusi from Kingston Business School.

Their research also found that web banners which warned internet users about the potential inaccuracy of information were ineffective in limiting its circulation.

The audience was just as likely to share content labelled as unverified, according to the KU team.

"The belief in fake news stories about healthcare is understandable. Most people do not have specialist medical knowledge, so if claims are put in a way that sounds like they make sense, why would the public not believe them?" Professor Favato said.

"One of our most concerning findings is that prior exposure to stories increases credibility — repetition counts, so the more someone sees something, the more they believe it."

KU said that participants in the study were randomly assigned to two groups, then shown social media style posts about six real and six fake news stories and asked whether or not they would share them on Facebook.

One of the groups saw web banners warning them about the credibility of the fake news posts, while the other did not.

Later, participants were shown the same 12 stories again, along with 12 new ones, and asked to rate whether these were true or false.

Even when a story was recognised as fake, the probability it would be shared was still higher than 50 per cent, Professor Favato said.

KU pointed out that vaccine hesitancy named as "one of the 10 biggest global threats" by the World Health Organisation (WHO) recently.

Professor Favato called on media companies to step up in the fight against fake or misleading news.

"Media organisations publishing fake news stories have a responsibility to act.

"If a story is not reliable, we recommend a publisher should have two choices — either delete the post or use the search algorithm to ensure scientifically inaccurate stories are relegated to appearing at the end of search results," Professor Favato said.