In recent years, The BMJ has campaigned on transparency—the focus of our Open Data campaign, and an issue of vital importance if modern medicine is to retain the trust of doctors and the public, writes Trevor Jackson in this week’s Editor’s Choice.

Dabigatran was the first of the new oral anticoagulants licensed to prevent stroke in patients with non-valvular atrial fibrillation. It was approved by the US Food and Drug Administration in 2010 and by the European Medicines Agency for this use a year later. The drug’s unique selling point, said its manufacturer, Boehringer Ingelheim, was that it would need no monitoring, unlike warfarin.

But as Deborah Cohen reveals in The BMJ’s latest investigation, the company withheld important analyses from the regulators showing that monitoring drug plasma concentrations and adjusting the dose could improve safety. Instead, the company’s marketing strategy emphasised the no monitoring message.

Company documents revealed in the course of US litigation over dabigatran show how, with proper monitoring, and changing the dose as needed, major bleeds could be reduced by 30-40% compared with well controlled warfarin. But, as Cohen discovered, neither doctors nor regulators have ever been aware of these calculations. Instead, guidelines (including those recently issued by the UK National Institute for Health and Care Excellence) have recommended the new generation of oral anticoagulants such as dabigatran, in part because they don’t require monitoring.

In an accompanying Analysis article, Thomas J Moore and colleagues highlight the differences in how US and European regulators managed the safety problems of the new anticoagulant dabigatran, and ask both to think again and mandate plasma monitoring of dabigatran. And editorialists Rita Redberg and Blake Charlton point out that one of the problems is that dabigatran benefited from FDA programmes to stimulate innovation, “which also contributed to a less robust evaluation of risks and benefits.”

Our dabigatran page pulls together all the relevant articles in this investigation, and also provides access to key documents referred to in the investigation, showing modelling that Boehringer Ingelheim carried out.

Birte Twisselmann is web editor and obituaries editor, The BMJ.