In corrections systems nationwide, officials are grappling with decisions about geriatric units, hospices and medical parole as elderly inmates — with their high rates of illness and infirmity — make up an ever increasing share of the prison population.

At a time of tight state budgets, it's a trend posing difficult dilemmas for policymakers. They must address soaring medical costs for these older inmates and ponder whether some can be safely released before their sentences expire.

The latest available figures from 2010 show that 8 percent of the prison population — 124,400 inmates — was 55 or older, compared to 3 percent in 1995, according to a report being released Friday by Human Rights Watch. This oldest segment grew at six times the rate of the overall prison population between 1995 and 2010, the report says.

"Prisons were never designed to be geriatric facilities," said Jamie Fellner, a Human Rights Watch special adviser who wrote the report. "Yet U.S. corrections officials now operate old age homes behind bars."

The main reasons for the trend, Fellner said, are the long sentences, including life without parole, that have become more common in recent decades, boosting the percentage of inmates unlikely to leave prison before reaching old age, if they leave at all. About one in 10 state inmates is serving a life sentence; an additional 11 percent have sentences longer than 20 years.

The report also notes an increase in the number of offenders entering prison for crimes committed when they were over 50. In Ohio, for example, the number of new prisoners in that age group jumped from 743 in 2000 to 1,815 in 2010, according to the report.

Fellner cited the case of Leonard Hudson, who entered a New York prison at age 68 in 2002 on a murder conviction and will be eligible for parole when he's 88. He's housed in a special unit for men with dementia and other cognitive impairments, Fellner said.