Traumatic brain injuries kill millions of people around the world and leave many more with long-term disability.
Doctors can sometimes save lives with surgery and intensive hospital care, but a new international study suggests that some of the biggest improvements may need to happen before an injured person ever reaches an operating room.
Researchers led by Oregon Health & Science University, or OHSU, examined how traumatic brain injuries happen and how patients are treated in countries with very different levels of wealth and development.
The study included more than 2,000 patients treated at 100 hospitals in 29 countries between 2019 and 2022. The findings were published in Nature Medicine.
A traumatic brain injury happens when an outside force damages the brain. It can result from a car crash, motorcycle collision, fall, sports injury, assault or other accident. Injuries range from mild concussions to severe damage that can cause permanent disability or death.
The worldwide burden is enormous.
Tens of millions of people experience traumatic brain injuries each year, and the researchers noted that almost 5 million deaths are linked to these injuries. Survivors may face problems with memory, movement, speech, emotions and the ability to work or live independently.
The international study found that motor vehicle crashes were the largest single cause of traumatic brain injury overall. However, the pattern was not the same everywhere. The causes changed depending on a country’s population, transportation system, development and other local conditions.
In wealthier countries, for example, simple falls from standing height were an important cause of brain injuries among older adults. An older person may fall in a bathroom, on stairs or while walking and strike their head. Aging, weaker muscles, poor balance, vision problems and some medicines can all increase the chance of falling.
In other countries, road crashes involving younger people may make up a much larger share of serious brain injuries. Poor road conditions, limited helmet use, unsafe vehicles and weak traffic enforcement can all increase risk. This means one global prevention program is unlikely to work equally well everywhere.
The researchers also found a surprising pattern: hospitals in less developed countries appeared to see lower rates of traumatic brain injury than hospitals in wealthier countries. The authors warned that this does not necessarily mean people in poorer countries suffer fewer serious injuries. Instead, some patients may never reach a hospital where they can be counted.
Access to emergency care can vary enormously around the world. In some places, an ambulance can arrive quickly and transport an injured person to a trauma center within hours. In remote or low-income areas, reaching a hospital with the right equipment and specialists may take much longer.
Senior author Dr. Ahmed Raslan, chair of neurological surgery at OHSU School of Medicine, said some critically injured people in low-income regions may die before they can reach medical care. If that happens, hospital-based studies can underestimate the true size of the problem.
Better emergency transport and access to trauma services could therefore save lives as well as improve the accuracy of health data.
The study was unusual because it compared injury patterns, treatment and outcomes across countries with different levels of human development. Human development measures consider factors such as income, education and economic conditions. This allowed the researchers to look beyond individual hospital treatments and examine the wider systems surrounding patients.
Lead author Dr. Joseph Nugent brought both emergency and surgical experience to the project. Before becoming a neurosurgeon, he worked as a paramedic in Baltimore and studied public health. He said that experience taught him that preventing severe trauma can sometimes accomplish more than treating the damage after it occurs.
For road injuries, prevention could include safer roads, stronger traffic rules, better emergency services and wider helmet use. Motorcycle and bicycle helmets can reduce the chance of severe head injury when crashes happen. Faster emergency response can also improve the chances that seriously injured people reach specialist care in time.
In places where older adults are frequently injured by falls, the solutions are different. Improving balance and strength, checking medications, treating vision problems and making homes safer may help prevent falls. Even simple changes such as better lighting, handrails and removing trip hazards can be useful for some older people.
The study’s greatest strength is its broad international reach. Collecting information from 100 hospitals in 29 countries gives researchers a much wider view than a study from a single health system. Medical students helped gather the data, creating a large international research network.
However, the results also have important limits. The study mainly describes people who reached participating hospitals, so it may miss deaths and injuries that occurred far from medical care. Differences in record keeping, hospital resources and which patients are admitted can also make direct comparisons between countries difficult.
The finding of apparently lower injury rates in less developed countries should therefore be interpreted carefully. It may partly reflect missing patients rather than a genuinely lower risk. Future studies that include ambulance records, community deaths and rural areas could provide a clearer picture.
Even with these limits, the main message is strong. Better brain surgery remains essential, but hospitals cannot solve the global burden of traumatic brain injury by themselves. Safer roads, helmets, fall prevention and faster access to emergency care could prevent injuries or keep them from becoming fatal.
The study also shows why prevention needs to be designed locally. A program aimed at frail older adults in Oregon may have little relevance in a country where young motorcycle riders account for many serious injuries. Understanding who is being injured and why is the first step toward preventing the next brain injury.
