How is a "secure hospital" different from a "prison"? Presumably the patient can't leave, which means locked doors, barbed wire fences, etc. If the patient is violent, that means security personnel, meals through slots in the door, etc.

"secure hospital" is just a euphemism for "prison"

He was put in two different secure hospitals, but he attempted to murder a patient at both. The prison service and the forensic psychiatry service have thus far been unable to change Bronson's violence and hostage-taking behaviour; solitary confinement thus far appears to be the only reasonable option to protect society from Bronson.

He is an outlier and is in no way representative of the broader prison population, but he does rather puncture the case for abolitionism.