Ambulance bosses have reassured the public the systems used to dispatch emergency vehicles are up to scratch after it was revealed that a woman died when the ambulance sent to her was diverted to another incident.

Bonnie Mason, 58, died after falling 12 feet in her home in Eye, Suffolk, last May. Paramedics from East of England Ambulance Service took 38 minutes to attend the scene.

Mrs Mason’s first ambulance was sent to treat a drunk woman who had fallen on to the pavement in Thetford, Norfolk.

A second ambulance was dispatched a short time after the first one, said a spokeswoman for the ambulance trust.

In the control room an automated computer system prioritises emergency calls before dispatching ambulances.

Falls of more than six feet were deemed to require a category B response, which means paramedics should aim to be on the scene within 19 minutes.

However, since the incident, the system has been upgraded and falls are now also assessed by the symptoms of the patient.

A spokeswoman for the East of England service - which covers Suffolk, Norfolk, Essex, Cambridgeshire, Hertfordshire and Bedfordshire - said that after the incident it contacted the software manufacturers to express concerns about the system.

She said that the computer system was upgraded in June last year.

“We used v11.3 of the Advanced Medical Priority Dispatch System from June 2008 to June 2009. The categorisation of falls in v11.3 was a national issue and we alerted the developers last year to our concerns about the fact that a long fall was prioritised as a category B response regardless of other factors.

“However v12.0, which we took live in June 2009, addressed this. AMPDS is a medically approved internationally utilised system which our highly trained control centre staff have used safely for a number of years to help determine the most appropriate response and the best outcome for our patients.”

She said the new system has been implemented in the 12 ambulance trusts around England.