In the UK, the term is discouraged in favor of two more precisely defined terms that have been strongly recommended by the Royal College of Physicians (RCP). These guidelines recommend using a "continuous vegetative state" for patients in a vegetative state for more than four weeks. A medical determination of a "permanent vegetative state" can be made if, after exhaustive testing and a customary 12 months of observation, a medical diagnosis is made that it is "impossible" by any informed medical expectations that the mental condition will ever improve. Hence, a "continuous vegetative state" in the UK may remain the diagnosis in cases that would be called "persistent" in the US or elsewhere.