Unexpected staff shortages in ambulance services are costing lives, with patients significantly more likely to die within 24 hours when ambulance crews are unexpectedly off sick, according to new research from the University of Surrey and the University of York.

The findings suggest that older people, those with the most serious conditions and patients needing care during busy winter periods are the most affected.

Using data from more than 11 million ambulance journeys to emergency departments in England between 2013 and 2018, researchers found that when unexpected ambulance staff sickness was higher than usual, deaths within 24 hours of hospital arrival increased by 0.78%. Planned absences, such as annual leave or study leave, had no comparable effect, highlighting the unique impact of unexpected sickness on frontline services.

The study, published as a discussion paper, reinforces the importance of maintaining a resilient ambulance workforce. While hospitals often receive the attention during NHS pressures, the evidence suggests that ambulance delays and staffing shortages before patients reach emergency hospital departments can have lasting consequences that hospitals cannot always overcome.

The team linked NHS ambulance workforce records with hospital and mortality data, analysing more than 11 million emergency department attendances across England. By comparing patients treated at the same hospitals but served by different ambulance stations experiencing varying levels of unexpected staff sickness, they were able to isolate the effect of ambulance staffing shortages on patient survival.

Giuseppe Moscelli, principal investigator of the study and Professor of Economics at the University of Surrey, said:

"When someone dials 999, every stage of the response matters. Our findings show that unexpected staff shortages in ambulance services can make the difference between life and death, particularly for patients who are already most vulnerable. This is about far more than workforce management. It is about ensuring people receive the right care quickly when every minute counts."

The researchers argue that strengthening ambulance workforce resilience should be seen as a patient safety priority. Measures that improve staff retention, reduce burnout and help services cope with sudden spikes in sickness could have a direct impact on survival rates, particularly during periods of peak demand.

Professor Cheti Nicoletti, co-author of the study and Professor of Economics at the University of York, added:

"Ambulance crews are the first link in the emergency care chain, yet their role is often overlooked when discussions focus on pressures facing the NHS. Investing in the people who deliver frontline emergency care is not simply about supporting staff. It is an investment in better outcomes for patients and a more resilient health service."

ENDS