[3] Heneghan is a Professor of Evidence-based medicine at the University of Oxford, NHS Urgent Care General Practitioner, and co-director of the Global Centre for Healthcare and Urbanisation.
[18] On 21 September 2020, Heneghan alongside Sunetra Gupta, Karol Sikora and 28 signatories wrote an open letter to the UK prime minister, chancellor and chief medical officers asking for a rethink of the government's COVID-19 strategy.
Sonia Sodha of The Guardian argued that Heneghan had made scientific errors because he had misrepresented a Danish randomized controlled trial which studied infection transmission rates on people who wore face masks.
[22] Kamran Abbasi, executive editor of the British Medical Journal (BMJ), also criticised Heneghan's claims about face masks because he believed his interpretation of the Danish study was inaccurate.
However, Abbasi stressed that he believed it was wrong that Heneghan's opinion be marked as “false information" on Facebook because, as he wrote in the BMJ, "disagreement among experts, especially about interpretation of a study, is a common occurrence.