The 111 service, which operates 24 hours a day, is managed by a team of professionals who offer treatment and advice to patients.
It was initially set up to try and ease pressures on unscheduled care in the Welsh NHS and stop people from unnecessarily attending A&E departments.
Currently the 111 service is only available to people living in Abertawe Bro Morgannwg University Health Board – which covers Bridgend, Neath Port Talbot and Swansea – and Carmarthenshire where it was launched as a pilot in October 2016.
The pilot tested the practicalities of combining NHS Direct Wales and the GP Out of Hours services.
The decision to roll it out nationwide followed an independent evaluation of the pilot.
It found the service received more than 71,000 calls in the first six months of operation, with 95% or survey respondents saying they were “satisfied” or “very satisfied” with the advice they were given.
Although the changes cannot be wholly be attributed to 111 the evaluation found a 1% decrease in A&E attendance in the Abertawe Bro Morgannwg UHB area during the first six months of service.
There was also a reduction in the number of ambulances taking patients to emergency departments.
However this change was mainly seen in non-urgent journeys – down by just over 25% during the evaluation period.
Health Secretary Vaughan Gething said the 111 service will be rolled out nationally over the next three years.
He said: “I’m very encouraged to see evaluation which suggests a link between 111 and a decrease in ambulance conveyance.
“It is also clear from feedback that this service has been valuable in supporting patients and helping the NHS to treat patients with urgent care needs more effectively.
“We’ve been open and honest about the pressure our emergency departments are under, particularly this winter.
“People can help make a difference by using our health service sensibly.
“The 111 service will support people to receive the most appropriate services for their needs at the right time and in the right place.”
Chris Powell, the Welsh Ambulance Service’s area manager for 111/NHS Direct Wales, added: “As the hosts of 111 we’re really pleased by the progress made and the encouraging feedback received during the early stages of the pilot.
“People living in the Abertawe Bro Morgannwg and Carmarthenshire areas have been reaping the benefits of 111 for many months now and soon everyone in Wales will have access to this service.
“This is another step towards a more modern approach to delivering urgent care and we look forward to building on the success of 111 to date.”
To improve the 111 service as it develops current staff were asked to complete a survey.
While the majority of respondents (62%) believed the service was well implemented some areas for improvement were also highlighted.
Nearly three-quarters of call handlers (71%) who responded said the call screening prioritisation tool (CSPT), which is used to diagnose the patient, was inadequate.
Respondents noted they found the system is “too rigid” when diagnosing illnesses and offering advice.
They also said it was “slow and difficult to operate”, particularly at times of high demand.
However, despite this lack of confidence in the clinical decision-making tools, 75% of respondents noted that they believe patients were always or often directed to the right service.
The annual running cost of running the service across Wales was estimated at just under £1.7m but this was found to be offset by cost savings to other parts of the health service.
The evaluation of the 111 service was undertaken by Public and Corporate Economic Consultants (PACEC) in conjunction with the University of Sheffield.
Their report stated: “The 111 Pathfinder has been well implemented.
“The service also performed well against the agreed standards. For example, 94% of total calls were answered within 60 seconds and the average triage times for urgent calls was three minutes compared to a standard of 20 minutes.
“It has been difficult to disaggregate the impacts of the 111 Pathfinder from that of other ongoing health interventions in Wales.
“However a review of statistics and key datasets in ABMU and across Wales suggests that the 111 Pathfinder has contributed towards improvements in other parts of the healthcare system such as a reduction in ambulance conveyances and a reduction in ED [emergency department] attendances in ABMU, whereas other health board areas experienced increased attendances during the same period.”