People aged 66 and above accounted for 89.5 percent of the 1,632 deaths indirectly linked to the Great East Japan Earthquake as of March, the government said Friday.
The total includes those whose health deteriorated after being evacuated in the aftermath of the twin disasters, which claimed the lives of nearly 20,000 people in Tohoku.
Among the region's worst-hit cities, Minamisoma in Fukushima Prefecture had the largest number of indirect deaths, at 282, followed by 178 in Ishinomaki, Miyagi Prefecture, and 143 in Sendai.
The government's Reconstruction Agency plans to examine the causes of indirect deaths in the three prefectures that suffered the worst damage — Iwate, Miyagi and Fukushima — until late June, and compile preventive measures for release possibly in early August.
"The study will be important for considering how best to manage the lives of evacuees and prepare for future disasters," reconstruction and disaster prevention minister Tatsuo Hirano said during a government panel meeting.