The findings suggest that rolling the scheme out across the UK could help practices avoid huge numbers of unnecessary appointments and improve access for patients.
The 11,000-patient Teviot Medical Practice in Hawick, Scotland added a message to its telephone system over winter to encourage patients to consider self care if their symptoms matched those of a common cold.
The message was added to the practice's phone system from November 2017 to March 2018. Researchers counted numbers of callers who continued through to speak to a receptionist after hearing the message, along with the average waiting time to the third available GP appointment, and compared this with data for the previous year.
Findings published in BMJ Innovations showed a 5.5% reduction in calls continuing through to reception 'when the incidence of the common cold is at its highest' and a 3.9% drop throughout the five-month period. Meanwhile, the study found that 'the mean waiting time to the third available routine appointment reduced by 21%'.
Dr Robin Kerr, a partner at the practice, told GPonline he had been sitting at home over a recent Christmas period with flu, wondering if he had picked the illness up from a patient who came in for an unnecessary appointment.
'As I was lying in bed I was thinking how could I have stopped this. By the time the patient comes in for an appointment with a cold or flu the time has passed - it's no good saying "next time you have a cold, consider self care".
'But at the moment when they think they need a GP appointment, right at that instant to make them think: "Hang on, maybe I could manage this myself after all" - it can make a difference.'
The researchers cited evidence that up to 7% of GP appointments 'could have been dealt with by a community pharmacist or with self-management'.
Meanwhile, NHS Digital data show that numbers of GP practice appointments increase by 10-15% in winter months compared with summer - reflecting in part the increased burden on general practice of seasonal respiratory illness.
Dr Kerr said that the message had helped his practice 'make sure we see those we need to see and encourage those who can to manage themselves'.
A practice-based pharmacist who works at the Teviot Medical Practice liaised with pharmacies in the local area so that they were 'aware and on board'.
Dr Kerr said using the message had been 'good for staff morale' because it had eased pressure on reception staff. He said: 'There's a good team spirit where we work - the staff know GPs have got their backs.'
A number of other practices in the area have now adopted the phone message. Dr Kerr added: 'We're keen to see if other GP practices would like to adopt it - it should be straightforward for others, knowing it's been tried and tested already.'