BOP data were obtained on the following:

• Monthly counts, by prison, of incidents in which inmates assaulted other inmates or corrections officers and whether a weapon was used.

• Monthly counts, by prison, of uses of force by corrections officers.

• Monthly counts, by prison, of homicides and suicides.

• Monthly counts, by prison, of grievances filed complaining about medical or mental health care.

• The monthly census for each prison.

All of these measures were obtained for both the predemonstration and demonstration periods. Rates were created using facility census figures, and differences in rates between the predemonstration and the demonstration periods were tested.