Deaths attributable to dementia as an underlying cause more than tripled from 2000 to 2017, according to a report released Thursday by the Centers for Disease Control and Prevention.

In 2017, there were 261,914 such deaths reported in the United States, up from 83,694 in 2000, said researchers from the CDC’s National Center for Health Statistics. Alzheimer’s disease accounted for more than 46% (121,404) of the deaths attributable to dementia as an underlying cause in 2017.

“Alzheimer disease was the sixth leading cause of death in 2017,” the authors wrote. “If all four dementia causes [unspecified dementia, Alzheimer’s, vascular dementia and other degenerative diseases of nervous system] were counted together, dementia would have been the third leading cause of death in the United States in 2017.”

An additional 129,700 deaths in 2017 had dementia listed as a contributing cause of death on the death certificate.

The majority of deaths attributable to dementia (60.4%) occurred in nursing homes, other long-term care facilities (which the CDC defines to include assisted living communities) and hospice, according to the report. Home was the second most common setting, at 22.9%, followed by medical facilities, at 8.7%.

Dementia-related deaths have been trending upward since 2000, with slight year-over-year decreases noted only from 2008 to 2009 and from 2015 to 2016.

“As the population ages and mortality due to other chronic diseases (e.g., heart disease) declines, a larger proportion survives to ages where the risk for dementia is highest. This may explain, in part, the observed increase since 2000,” the authors wrote.

California, Texas, Florida, Pennsylvania, Ohio, New York and Illinois had the highest number of dementia-related deaths, whereas Tennessee, Kentucky, South Carolina, Maine, Alabama, Oregon and North Carolina had the highest age-adjusted dementia-related death rates.

“Geographic differences in death rates for dementia could be due to factors such as variation in practices of certifiers of death (including specialized guidelines for coding dementia identified in some locations), differing awareness of Alzheimer disease and other dementias as chronic diseases that can lead to death, and differences in socioeconomic status and racial and ethnic distributions across states,” the authors noted.