A government research institute on Sunday released a white paper on elderly people going missing, which it said happens about half a million times a year, or 1,370 times a day on average, The Beijing News reported.

The report — yet to be made public — was authored by the Zhongmin Social Assistance Institute, which falls under the Ministry of Civil Affairs. It pointed to dementia, mental illness, and lack of care as the main reasons behind elderly getting lost and going missing.

Another explanation, according to the report, is the rising phenomenon of “left-behind elderly” — aging parents whose children work outside of their hometowns. Chinese people over the age of 60 numbered 222 million in 2015, and more than half of them live without their children, mostly in rural areas. That number continues to grow.

Of the aging population who have gone missing, a majority had memory loss issues, said the report. Some 78 percent had been diagnosed with a mental disease, in most cases Alzheimer’s.

News of elderly going missing, and sometimes dying as a result, regularly appears in Chinese media. Ninety-year-old Huang Yunya lived alone and disappeared last month in a rural area in eastern China. He was found dead the next day near a highway.

Following decades of strict family planning policies, China’s population is aging at a rapid pace. Care for the elderly is struggling to keep up with demand, however, as younger generations move away to cities for better work opportunities.

“The situation of elderly people going missing is more serious in rural areas than in cities,” said Yang Fan, a research fellow on aging at Shanghai Jiao Tong University. “Few care services can be provided to old people in rural areas,” he told Sixth Tone. “Even if they have memory issues, elderly couples or singles have to take care of themselves.”

(An elderly man sits in a wheelchair in front of his house in Dongguan, Guangzhou province, Sept. 17, 2015. Chen Yiqi/VCG)