Almost one in five UK doctors has had direct experience of an incompetent or poorly performing colleague in the past three years, finds a survey of professional values, published online in BMJ Quality & Safety.
Nearly three out of four of these doctors said they had sounded the alarm, but one in three of those who had not done so gave fear of retribution as the reason.
The study authors canvassed the views of almost 2,000 US doctors working in primary care and hospital medicine and over 1,000 of their UK peers in 2009 about various aspects of professional behaviour.
Topics included quality and safety issues, conflicts of interest, and attitudes to patients. Almost two thirds of US doctors and four out of 10 UK doctors responded.
Somewhat surprisingly, only 8 out of 10 respondents in both countries strongly agreed that patient welfare should come before their own financial interests.
And only around 6 out of 10 felt that they should disclose any financial relationships they had with pharma companies to their patients. Most respondents had received gifts/samples from these companies.
And not all doctors agreed that it was "never appropriate" to have a sexual relationship with a patient.
When it came to the quality of their own performance, twice as many US as UK doctors agreed that periodic recertification (revalidation) was necessary. But only just over half of US doctors agreed with this, despite recertification having been in place for several years in the US. Revalidation for UK doctors is due to start in 2012.
When it came to dealing with a colleague's performance, almost one in five (19%) UK respondents said they had had experience of an impaired or incompetent colleague during the previous three years, compared with 16.5% of US respondents.
Nearly three out of four UK doctors (72%) and nearly two thirds of their US peers (65%) said they had alerted relevant individuals/bodies. But of those who didn't, one in three UK doctors said this was because they feared retribution. Just 12.5% of US doctors gave this as their reason.
Between one in four (UK) and one in five (US) respondents said they hadn't sounded the alarm, because they thought someone else was taking care of the problem.
UK doctors were also less likely than their US peers to completely agree that all the pros and cons of a procedure should be fully explained to a patient, but when things went wrong, UK doctors were more likely to agree that significant medical errors should be disclosed.
There was some evidence that doctors in both countries paid lip service to equality issues. The overwhelming majority of respondents agreed that they should strive to minimise disparities in care due to race, gender, or religion. But fewer than one fifth of doctors in either country had actually looked at data on health inequalities in their practice.
"Especially at times of major healthcare reform, as both the USA and UK currently face, doctors have an important responsibility to develop their healthcare systems in ways which will support good professional behaviour," conclude the authors.