Complaints about the out-of-hours services provided by GPs are on the increase, according to the Medical Defence Union, which advises UK doctors on legal and ethical issues.
A new survey by the MDU suggests that problems occurring outside usual surgery hours now account for 10% of all complaints reported by members - that's a tenfold increase since 1997.
Nearly a third of complaints came after patients died, and a similar number were made because patients were subsequently admitted to hospital after calling the out-of-hours provider.
Dr. Karen Dalby of the MDU commented: "The rising number of complaints about out-of-hours care is perhaps surprising given the relatively small number of these consultations that take place, compared to those during surgery hours."
She claimed that the reasons for the increase in complaints were unclear, but suggested that it could be due to the change in the way services are provided.
In recent years, more GPs have been switching to out-of-hours co-operatives, whereby a group of GPs from different practices agrees a shift pattern to reduce the frequency of their 'on calls'.
"This means that patients will often be seen by, or talk to, a doctor who is not their usual GP and so may not know their medical history," Dr. Dalby explained.
"Most out-of-hours doctors do not have access to the patient's medical records and must base any decision about the urgency of the case on the information they receive from the person who took the call."
And the number of co-operatives is likely to increase with the introduction of the new GPs' contract, as doctors will be allowed to opt out of out-of-hours services, leaving the primary care trust to ensure adequate provision for each area.
But the MDU claims that the situation need not get worse if doctors ensure that they communicate effectively, and ensure that GPs providing cover are aware of potential emergencies - such as terminally and chronically ill patients.
The MDU's figures register a relatively minor number of complaints overall - just under 2,000 for the year. And it notes that the majority were resolved at practice level.
However, the Department of Health's figures show that nearly 43,000 complaints were made against doctors.