A new study by the National Institute of Standards and Technology shows scientifically for the first time that an individual’s ability to respond quickly to a residential fire determines who dies and who gets injured.

According to the institute (NIST), fire-related deaths are more likely among people who aren’t in robust health and primarily 65 and older, while non-fatal injuries in fires occur more often in adults 20 to 49 years old.

The study’s findings, published in the research journal Injury Prevention, suggest that vulnerability to fires in homes could be mapped for communities based on age demographics, and measures to prevent fire deaths and injuries could be targeted to the appropriate populations to maximize their effectiveness.

David Butry, chief of applied cconomics for NIST, said previous studies tried to link fire deaths and injuries in homes to the overall fire risk rather than the role of occupant vulnerability once a fire was underway.

“Those studies couldn’t say whether the elderly disproportionally fall victim to fires because they live in places with higher-than-average fire ignition threats or because they are unable to respond quickly to a fire and get to safety,” he said.

In their study, Butry and NIST economist Stanley Gilbert used U.S. Census data and a national database managed by the federal Department of Homeland Security to document the number of fires and injuries and fatalities from fires for the five-year period from 2009 to 2013. What Butry and Gilbert found was that home fires resulted in an average of 2,740 deaths and 13,300 injuries per year, accounting for 84 percent and 77 percent of all fire-related fatalities and injuries, respectively. Thirty-two percent of the deaths were among people 65 and older, although they represented only 13 percent of the U.S. population. In contrast, adults between ages 20 and 49 made up 42 percent of the population but represented only 25 percent of home fire deaths.

The opposite proved true for injuries from home fires. Butry and Gilbert found that 20 to 49-year-olds experienced 50 percent of the non-fatal injuries, while the 65-or-older group were recorded at 13 percent. Neither the disproportionally high death rate among the elderly nor the high injury rate among young to middle-aged adults could be completely explained by the overall risk of a fire occurring.

“If fire risk was the critical factor in determining the number of deaths and injuries, then we should have seen no differences in the rates for the elderly and adults 20 to 49,” Butry explained. “But we did find differences between the age groups, so another factor had to be involved.”

Gilbert said the study strongly suggests that communities should evaluate and address home fire risks for occupants based on physical “frailty, especially in elderly populations. Therefore, measures to overcome this population-specific vulnerability, such as automatic sprinklers in bedrooms, may help reduce the number of fatalities.”

The findings of the NIST study will be incorporated into a recently launched national, interactive online proigram that defines fire risk environments. Known as the Fire-Community Assessment/Response Evaluation System, or FireCARES, the system gives fire departments a decade of research on structure fires and related deaths and injuries. It also provides building plans, residential and mobile housing locations, public health and census data, and statistics on vulnerable populations.

“The overarching goal of FireCARES is to assist emergency responders in making sound decisions, based on quantifiable data,” said Lori Moore-Merrell, assistant to the general president of the International Association of Fire Fighters. “The insights gleaned from this study not only have immediate impact on the risk assessment portion of the FireCARES project, but also on overall emergency response planning in local communities.”