IPART conducted a Hospital Costs and Outcomes Study for selected NSW Hospitals for the NSW Department of Health. The main purpose of the study was to produce a body of evidence that could be used by clinical experts to promote clinical best practice and efficiency. We were asked to compare costs, outcomes and hospital and clinical practices in 5 major NSW hospitals. The 5 hospitals were Royal Prince Alfred Hospital (RPAH), Gosford Hospital (GH), Royal North Shore Hospital (RNSH), Bankstown-Lidcombe Hospital (BLH), and John Hunter Hospital (JHH).The study was conducted between September 2009 and July 2010 and involved data analysis, consultation with staff in each of the hospitals and consultation with a number of clinical experts.IPART undertook its analysis at two levels:- at the hospital-wide level, and- using 11 clinical case studies.At the hospital-wide level, IPART compared resource management, clinical costing and clinical coding practices. At the detailed case study level, IPART selected 11 specific clinical conditions or procedures as case study areas, e.g., hip joint replacement, cataract and lens procedures and obstetric delivery. Clinical aspects of the study were overseen by a group of medical and surgical experts.IPART's analysis is part of a wider study being undertaken by NSW Health. In the final stages of the wider study, IPART's recommendations and findings will be reviewed by clinical experts to assess if there are clinically significant differences in outcomes or practices and if any changes to clinical practices should be recommended. Observations from IPART's study will also help to improve cost efficiency and data quality across the health system.