Academic institutions are breaching rules by failing to report the results of clinical trials, new research shows.

A study, published in journal BMJ, found “poor” compliance with EU regulations which require outcomes to be posted to a central register within 12 months.

Informed choices about the best treatment for patients cannot be made unless all results are reported, the lead author said.

Only half (49.5%) of 7,274 trials where results were due reported results, analysis by researchers at the University of Oxford found.

More than two thirds (68%) of trials sponsored by pharmaceutical companies posted results, compared to just 11% of those without a commercial sponsor, such as universities, hospitals, governments and charities.

Rules, which mean all trials conducted in Europe on medicinal products should report their results to the EU Clinical Trials Register within 12 months of ending, are “commonly being breached”, the researchers said.

Lead author Dr Ben Goldacre, director of the DataLab at the University of Oxford, said: “This problem strikes to the heart of evidence-based medicine.

“We cannot make informed choices about which treatments work best, as doctors and patients, unless all results are reported.

“We hope that our data will help trial sponsors to move fast and get their houses in order.”

He added: “We would hope that public pressure and the ethical need for trial reporting should be enough. But the EU Clinical Trials Regulation is coming into force next year.

“It will bring substantial financial penalties for sponsors in breach of reporting requirements. All trial sponsors – especially universities – must get their house in order now.”