A record number of American adults are now dying with a dementia diagnosis, new research shows. Yet, that increase of 36% from two decades ago may have more to do with better record-keeping than an actual rise in dementia cases, the study authors said.

About half of all older adults are diagnosed with dementia before their deaths, according to a study from Michigan Medicine–University of Michigan. The study used data from 3.5 million people over the age of 67 who died between 2004 and 2017, including bills submitted to the Medicare system in the last two years of their lives.

About 35% of these end-of-life billing claims mentioned dementia in 2004. By 2017, that statistic was 47%. About 39% of people had at least two medical claims mentioning dementia in 2017, compared to 25% in 2004

This grew most substantially when Medicare allowed hospitals, hospices and doctors' offices to list more diagnoses on their requests for payment, according to the study. During this time, the National Plan to Address Alzheimer's Disease also increased public awareness and quality of care while offering more support for patients and their caregivers.

The research provides a starting point for individuals to talk to their families and health care providers about what type of care they would like to receive if they are diagnosed with Alzheimer's disease or other cognitive decline, the researchers said.

End-of-life care for patients with dementia has also changed in these years, including a lower percentage who died in a hospital bed or intensive care unit, or who had a feeding tube in their last six months of life. Nearly 63% received hospice services, up from 36%. This coincided with a national increase in hospice care overall.

"This shows we have far to go in addressing end-of-life care preferences proactively with those who are recently diagnosed, and their families," said senior study author Dr. Julie Bynum, a professor of geriatric medicine at Michigan Medicine.

"Where once the concern may have been underdiagnosis, now we can focus on how we use dementia diagnosis rates in everything from national budget planning to adjusting how Medicare reimburses Medicare Advantage plans," she added in a Michigan Medicine news release.