It was meant to be a carefree family bike ride by the sea.

Instead, it marked the beginning of a tragedy that would cost 13-year-old Martha Mills her life - and spark a nationwide change in patient safety that has already helped save hundreds of others.

Martha, a fit and healthy teenager, suffered a devastating internal injury when she fell onto her handlebars during a ride in Wales in 2021.

Doctors initially believed she would recover but weeks later, after her condition deteriorated in hospital and her family's fears went unheard, she died from septic shock.

An inquest later found she would probably have survived if medics had recognised the warning signs sooner and moved her to intensive care.

Her death prompted her parents, Merope Mills and Paul Laity, to campaign for a major change in how hospitals respond when patients deteriorate.

The result was Martha's Rule, which gives patients, families and NHS staff the right to demand an urgent second opinion if they fear someone's condition is getting worse.

Since being introduced in 2024, the system has already led to more than 500 patients receiving potentially life-saving care, including transfers to intensive care or specialist units.

Figures from NHS England show that 12,301 calls were made to Martha's rule helplines in the first 18 months of the scheme.

Of these, 4,047 were linked to patients whose condition was deteriorating, and 1,786 led to changes in treatment.

A total of 534 cases resulted in life-saving interventions, such as patients being moved to specialist wards.

More than 1,500 NHS staff have used the rule to raise concerns, with over 1,000 cases identifying patients who were rapidly deteriorating.

Martha's parents said the figures were 'clear evidence' that problems such as hierarchy and poor communication still affect patient care.

They said: 'It is hugely encouraging for us that 1,000 clinically-trained staff have already used Martha's rule.

'This is also clear evidence that issues such as hierarchy, poor communication and some doctors' resistance to being challenged affect hospital care every day. Such factors were crucial to any explanation as to why Martha lost her life.'

Health Secretary Wes Streeting said the scheme was already having a 'lifesaving impact'.

He added: 'I want a health service that listens to patients, to families and to the staff who care for them.'

The rule is now being rolled out across hospitals in England following a pilot at more than 140 sites.

However, awareness remains low. A survey found just 32 per cent of people had heard of the escalation process, with those who had been to university four times more likely to be aware of it.

Professor Aidan Fowler, national director of patient safety at NHS England, said it was 'really encouraging' to see staff using the system to flag concerns.

Dr Lavanya Thana, of the National Institute for Health and Care Research, said the scheme showed a clear commitment to ensuring patients and families are heard.

But for Martha's parents, nothing will ever bring their daughter back.

Writing previously, her father said his daughter had been denied 'anything that resembled a full life'.

Her mother added: 'I shall never be able to forgive the hospital, but I can at least work for something good to emerge from this nightmare.'