Almost one in four of the researchers and clinicians who helped develop clinical guidelines have been found to have ties with big pharma that were not revealed at the time, an Australian study finds.

Health academic and writer Dr Roy Moynihan (PhD) and colleagues have examined the “potentially relevant” undisclosed financial ties between the health professionals who develop guidelines listed on the NHMRC’s database and pharmaceutical companies.

They found that 24% of guideline authors across 10 key health priority areas had a financial link with a pharmaceutical company “active in the therapeutic area” that was not revealed at the time the guidelines were developed.

And 23 of the 33 guidelines studied featured at least one writer with such an undisclosed relationship, in findings that probably underestimate the extent of links, the researchers say.