A patient was somebody who was treated at a medical facility. (TV: The Empty Child, New Earth)
Novice Hame of the Sisters of Plenitude, based at the New New York Hospital, boasted that they never lost a patient. (WC: Tardisode 1)
The patients at Albion Hospital that were affected by the Empty Child plague all had the exact same injuries. (TV: The Empty Child) They were later healed of all injuries and ailments, including those they had before contracting the plague. (TV: The Doctor Dances)