Another thing that is included in proposed staffing legislation is a requirement for a patient acuity system. However, very few hospitals currently use patient acuity systems. In a recent study in Pennsylvania, less than 20% of hospitals were using patient acuity systems, down from over 40% ten years ago. Key reasons cited for discontinuing the use of patient acuity are problems with validity, reliability, time and cost involved, and the fact that the data lacked credibility with staff.