Elderly people who were in the habit of socializing with friends before the 2011 Great East Japan Earthquake and tsunami are half as likely to have died since the disaster, a survey found.

A Tohoku University-led research team said Feb. 16 that the findings underscore the importance of measures to prevent disaster victims from becoming isolated.

“Countermeasures to prevent isolation of elderly people after disasters are important,” said Jun Aida, an associate professor of public health at the university, who was a member of the team. “Strategies such as evacuating them in groups will be necessary so they can maintain their connections with others they built before the disasters.”

The scientists examined data on 860 residents aged 65 or older in Iwanuma, Miyagi Prefecture, who lived in areas inundated by the tsunami. While 33 of them died on the day of the earthquake, a further 95 passed away over the three-year period following it.

The team studied the mortality rates among those who said they “socialize with friends” or “do not” in a questionnaire survey conducted before the March 11, 2011 earthquake, and discovered that the risk of death during the three-year period for the sociable group was just 46 percent of that for the antisocial group.

According to the researchers, those who regularly interact with friends were able to get along with others in evacuation centers and elsewhere after the disaster more easily, likely exerting a positive impact on their health and well-being.

The findings have been published in the British scientific journal Scientific Reports.