Texas Health Resources Inc., the largest hospital system in North Texas, has formed a temp agency with an Arlington-based medical staffing company to both save money and fix its nursing shortage. The joint venture with Medfinders Inc., operating as Texas Health SingleSource Staffing, will oversee the staffing of all per-diem nurses for Texas Health's 14 hospitals across North Texas. By having an in-house agency, Texas Health is better able to fill its 5% nurse vacancy rate and avoid costly overtime by paying temporary nurses to cover shifts of full-time nurses, said system representatives.