Background. Sicilian government has developed a very ambitious Reform through the Regional Law n. 5 (14th April 2009). Hospitals were requested to ensure the quality of care through monitoring of appropriateness and quality of service. The aim of this study was to assess variations of efficiency and organizational appropriateness of healthcare delivery before and after this Reform and to show patterns associated to different types of healthcare delivery organizations. Methods. This study was based on repeated cross-sectional data for 118 (out of 129) short-term, acute-care, non teaching-and-research Sicilian hospitals, in 2008 and 2010. Congestion and slacks analysis was used, with four inputs, two desirable outputs and two undesirable outp...