The age distribution did not differ significantly from that of the remaining prison population.
Those receiving interventions were investigated further and compared to the remaining prison population.
On his first full day in office in January 2009, Mr. Obama banned coercive interrogation methods and ordered the closing of the C.I.A.'s remaining prisons overseas.
The remaining four prisons (mean number of inmates 192, range 82 360) were chosen because they were considered representative for the country's larger prisons with medium to high security profiles.
In fact, there are about 12 or 15 of us, the last remaining prisoners on a prison asteroid, which is hurtling through space.
With the demise of the Confederacy, black P.O.W.'s were either paroled from the remaining Southern prison camps or simply walked away as their guards abandoned them.
Where gaps in the questionnaire data remained, prison administrative bodies and experts were contacted via e-mail or telephone and requests for specific information were made.
With that smaller number, some officials say, it would be easier to close Guantánamo and transfer the remaining detainees to prisons in the United States.
The remaining 1387 male prisons were stratified by U.S. region and population size with 222 additional facilities selected for participation.
