A runner who died after a broken leg sustained during a half marathon was misdiagnosed as a pulled hamstring was the victim of “gross failings and neglect”, a coroner has concluded.

Sarah-Jayne Roche, 39, who has two children, died as she was operated on 12 days after she collapsed during the Cardiff half marathon.

She attended hospital three times before the broken femur was diagnosed and died after developing deep vein thrombosis.

The coroner, Graeme Hughes, said on Thursday there were three “red flag opportunities” missed to x-ray Roche, leading to a “gross failure”.

Hughes found that had there been an x-ray, the operation would have taken place a week earlier.

The inquest previously heard Roche, from Beddau, near Pontypridd in south Wales, was running the race on 5 October last year to raise money for a Parkinson’s charity after her father, Alan, was diagnosed with the disease.

At the seven-mile point in the race, which she was running with her husband Steven, 42, she felt “a shooting pain up her leg” and came to a halt. She visited hospital on three occasions, where she was given painkillers and told to apply ice, but was not sent for an x-ray.

Hughes said: “I am satisfied, had she been x-rayed on October 7, 8 or 12, on the balance of probabilities she would have survived and not died on the 19 October.”

The coroner said there was a failure in Roche’s care when all three hospital appointments were “considered cumulatively”.

He said: “They do amount to a sufficient level of fault. There were three … red flag opportunities to procure an x-ray.”

The coroner added there was a “serious underestimation” of Roche’s condition and the fact her fracture was rare was “irrelevant”.

Hughes said: “Whilst undergoing surgery to fix a fractured femur at the Royal Glamorgan hospital Sarah-Jayne Roche developed pulmonary thromboembolism as a consequence of an undetected and undiagnosed deep vein thrombosis.

“She went into cardiac arrest and despite extensive resuscitation attempts died at 7pm that evening.”

He added there was a “gross failure on the part of clinicians” to develop correct diagnoses, contributing to the development of DVT, pulmonary thromboembolism and her death.

The coroner said there was “conflicting” evidence from Dr Tim Manfield, who saw Roche and her mother, Patricia Newman, on 12 October.

Newman claimed the doctor did not physically examine her daughter’s leg, despite being told it was “freezing cold”.

Manfield told the inquest: “That is untrue, I remember feeling the knee, thigh and hamstring and pulling on the lower leg.” Manfield also told the inquest that he ordered an ultrasound but the paperwork was never found.

The inquest heard Roche, a school worker, had set running the half marathon as a personal challenge to complete before she was 40.

Kamal Asaad, the medical director of Cwm Taf Morgannwg University Health Board, said: “We are deeply sorry about Sarah-Jayne’s death and would like to offer a sincere and unreserved apology to her family and friends for the failings in her care.

“Words are of little comfort at this distressing time but we would like to assure the family that changes have already been made to help prevent such failures in the system from happening in the future.

“A full investigation into the care she received was instigated immediately, and actions are being taken and closely monitored to address the shortcomings that were identified. These include strengthening our clinical processes, including x-ray procedures in A&E as well as our protocols for more detailed assessments and investigations before reaching a definitive diagnosis.

“We accept the coroner’s ruling and will now review all of his findings to ensure we fully address all of the failings.”