Oregon has the largest share of elderly inmates in the nation, according to a study released Tuesday by the Pew Charitable Trusts.
The scope of the study was between 2007 and 2011. During that time, more than 12 percent of Oregon's inmates were older than 55. That compares to just 4 or 5 percent in many other states.
"Older prisoners push up states' per-inmate health care expenses because like older people outside prison walls, older inmates are more susceptible to chronic medical and mental conditions," said study author Maria Schiff.
The study found Oregon paid about $7,300 per inmate on health care in 2011, a 21 percent increase over four years. Washington's costs dropped over the same period to about $7,000 per-inmate.
Some states have used geriatric parole to reduce prison health care costs.
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