Substantial staffing shortages and inadequate training at one NHS 111 helpline put patients at "risk of harm", including leaving urgent callers on hold for lengthy periods of time, a damning report has revealed.
One patient was left waiting for a call back for 22 hours.
The phone line, run by South Western Ambulance Service, has been ordered to make immediate improvements across the board after Care Quality Commission (CQC) inspectors slammed the "inadequate" operation.
CQC inspectors found that some patients were waiting too long to receive a call back, including one patient who was left for almost a day without hearing back from an adviser.
There were often not enough staff to take calls or to give clinical advice where needed.
The report reveals calls were sometimes answered by staff who were not trained to assess patients' symptoms, and said there was a risk that patients needing urgent attention were not given priority or could be put into a long queue awaiting call back.
Staff reported working long hours, with many feeling high levels of stress and fatigue.
There was also a high staff turnover and high sickness rates, while some had been denied annual leave because of staff shortages, the report found.
Prof Mike Richards, the CQC's chief inspector of hospitals, said inspectors had been working with NHS England, NHS Improvement and the local commissioners to ensure that their most urgent concerns around the triaging of calls were dealt with as soon as possible.
Although staff were supported in raising safety concerns, the report said, the trust failed to act to ensure these concerns were addressed.
The Chief Executive of the South Western Ambulance Trust, Ken Wenman, said that now they have the report they will be able to use the findings to improve the service over the coming months.
CQC has told the trust that it must make a number of "significat" improvements by a deadline of July 8.
- The trust must continue to review staff numbers to ensure patients can access timely care and treatment when first calling the service and when receiving a call back
- The trust must review the roles and responsibilities of Non Pathway Advisors (call handlers who are not trained to use the NHS Pathways triaging system) ensuring callers consistently receive the correct level of advice
- The trust must ensure that the call queues awaiting initial assessment and callback are robustly monitored and managed by staff with clinical authority to intervene and allocate resources.
The mother of a baby who died following a string of NHS failures, including being let down by the 111 service, welcomed the report - and said she hoped it would lead to improvements.
Melissa Mead from Penryn in Cornwall lost her son William at just 12 month's old to sepsis.
Earlier this year, a report into his death criticised GPs, out-of-hours services and a 111 call handler who failed to spot he had sepsis caused by an underlying chest infection and pneumonia.
"We have been waiting for a very long time with suspicions but now those suspicions have been confirmed obviously this shows that William's call isn't just a one-off error within the system," she said.
"Obviously when I called 111 I wasn't aware that William was seriously ill. We called them because we wanted reassurance, we wanted some kind of signposting guidance on what to do."