Patients arriving by ambulance had 86% higher odds of death or disability and more than double the odds of dying within three months compared with those using other transport. Researchers think this reflects severity bias: ambulances carry sicker patients, so the worst outcomes likely reflect injury severity rather than the transport itself.

"One of our most surprising findings was that measures often assumed to improve outcomes—such as ambulance transport and rapid transfer to major hospitals, which are similar to highly centralized trauma services—were not consistently linked with better recovery or survival," Davies said. "This does not mean that ambulances cause worse outcomes but suggests that investment in ambulance systems alone is unlikely to improve outcomes unless services are coordinated and appropriately resourced."

Does faster care always help?

The data offer a partial answer: no. Researchers found no evidence that reaching the hospital more quickly lowered the risk of death. Some delays before arriving were linked to lower disability later, possibly because minor injuries can wait while serious cases move first.

Stopping first at a nearby hospital for stabilization may help when a specialist hospital is far away, the authors note. Going directly to a major trauma center appears to help when one is close by.

How did outcomes vary across countries?

Country-level differences were stark. Patients in South Africa had the lowest odds of disability but the highest odds of mortality. Rwandan patients had the lowest odds of dying. Pakistani patients experienced substantially higher odds of death or disability combined than Ghanaians.

Age predicted worse outcomes. Gender, wealth, and education had little effect on in-hospital survival. After discharge, however, wealthier and better-educated patients recovered better—likely because they could access rehabilitation and follow-up care.

What do the authors recommend?

Corresponding author Dr. Leila Ghalichi, also from Birmingham, cautioned against copying trauma models from wealthy nations without local evidence.

"This does not mean ambulances or specialist trauma centers are ineffective," Ghalichi said. "Rather, it suggests that simply investing in expensive emergency systems is not enough. LMICs should be cautious about investing heavily in ambulance services and specialist, centralized trauma centers without ensuring they are well coordinated, properly staffed and supported by strong health systems. Better data and further research are needed to understand which trauma-care investments improve patient outcomes."

The authors argue that trauma systems should be built around local evidence, resources, and patient needs rather than transplanted from high-income settings.