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Patient Care

BLS Is Better for Survival—Now What?


Of every 100 major trauma patients who receive ALS ambulance response and treatment, 63, on average, will survive for 90 days.

If those 100 major trauma patients were instead to receive BLS ambulance response and treatment, an additional 15 might live that long who, with ALS care, would not have.

That’s the startling conclusion reached by Prachi Sanghavi, PhD, an assistant professor in the Department of Public Health Sciences in the Biological Sciences Division of the University of Chicago. Sanghavi examined nearly eight million random ambulance transports from 2006–11 and, using a propensity score weighting analysis, concluded that BLS care was associated with better trauma survival. Not only that, she says, but the same holds true for heart attack, cardiac arrest and stroke.

“What I found,” Sanghavi said in relating her findings at the Harvard Horizons Symposium, “suggests our ambulance system is in serious trouble.”

She weighs possible contributors to this phenomenon, including time to hospital (longer for more complex ALS care), the potential poor quality of some ALS interventions, and that some measures (e.g., aggressive fluid resuscitation) may best wait for the hospital, but is more concerned with how we ended up with such an ALS-heavy system and how we might change it.

“These decisions were not based on scientific evidence,” she says. “We have a lot of work ahead of us to fix our ambulance system. By carefully using data and statistics, we can study causality in real-world settings that are otherwise difficult to replicate in experiments. Powered with data, our generation can challenge the political and institutional inertia that supports practices in the absence of scientific evidence.”

See the whole talk at and find the research at

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