Millions of patients may have taken influenza drugs that have little or no benefit to them, according to an Australian-led study.
The study found that researchers paid by pharmaceutical companies were more likely to recommend antiviral drugs for flu and produced different recommendations to independent researchers conducting the reviews.
The study analysed 26 systematic reviews, a type of study considered to be the gold standard of evidence because they assess all existing studies on a topic using stringent guidelines.
Adam Dunn, lead author of the study and a health informatics expert at the University of NSW, said: “Systematic reviews summarise available evidence following strict protocols, so we expect findings from them to be consistent.
“But we found reviewers with ties to pharma introduced bias, as we found a disconnect between what their results showed and what they went on to recommend.”
The study, published in the journal Annals of Internal Medicine, concluded that benefits of the class of drugs, known as neuraminidase inhibitors, may eventually be found to have been inflated, which could prove highly costly to governments.
“Global stockpiling of antivirals was recommended by a panel from the World Health Organisation in 2002 and in 2009, governments around the world spent $6.9bn building stockpiles of oseltamivir [Tamiflu], an investment that remains poorly supported by available clinical evidence,” the study said.
Almost 80% of reviews written by researchers with financial ties were favourable towards the drugs, while 17% on independent reviews were positive, the study found.
Ray Moynihan, a senior research fellow at Bond University who has authored books on the pharmaceutical industry and overdiagnosis, described the work of Dunn and his colleagues as “highly valuable, critical work”.
“It’s incredibly encouraging to see this issue being examined in Australia, and that our researchers are at the cutting edge of some of the big, international debates occurring in medical and scientific evidence,” Moynihan said.
“We know from very reliable evidence that clinical trials that are sponsored by pharma tend to favour the sponsor’s drug, but what this paper is showing is that this bias has crept into what is considered the most reliable form of medical evidence, the systematic review.”
It was a worrying finding for patients, he said.
There needed to be a stronger push for independent research to be conducted without drug industry funding, he said, adding that public funding available through bodies like the National Health and Medical Research Council should be used instead.
“It is clear we have likely been misled about the benefits and harms of these drugs because so much of the evidence is tainted by a pro-industry or pro-drug bias,” Moynihan said.
“This is a cause for alarm as billions of dollars of public money has been invested into these drugs.”
Addressing concerns that harmful movements, like the anti-vaccination campaign, may use papers like Dunn’s as evidence not to trust doctors and medical advice, Moynihan said the study reinforced the importance of scientific evidence.
“Far from making people sceptical about science, this should reinforce its value in medicine,” Moynihan said.
“What we have in medicine is unfortunately a lot of marketing disguised as science, and this paper helps us realise that bring the best of the scientific methods forward to debate medical evidence can improve our knowledge.”
Much greater transparency in medical and scientific research and by drug companies was also needed, he said.
Dr Florence Bourgeois, a co-author of the paper and emergency medicine specialist at Boston Children’s Hospital in the US, said it was important that doctors talk to their patients about the safety and efficacy of the drugs.
But she acknowledged that could be difficult given the contradictions and uncertainties around them.
“The best thing is for patients to have a conversation with their healthcare provider about whether these drugs are the right choice for them,” she said.
“Clinicians, in turn, should decide on a case-by-case basis which patients are good candidates for the drugs, weighing the benefits and harms.”