[Public reporting on individual hospitals' quality: the risk of misinformation]

increasingly information on individual hospital' clinical performance is disclosed to the general public through lay mass media. Usually the explicit goal of those initiatives is to guide citizens' choice identifying the "best", centres. However, these efforts rely either on simplistic approaches in comparing the clinical performance of individual hospitals or on inadequate quality indicators. Therefore, this information may easily misguide the general public. In this paper, in order to highlight the problems implied, we consider two recent cases of mass media reporting on hospitals' quality.Two recent cases of mass media reporting on cardiac surgery centres' quality are considered: the BPAC study "Esiti a breve termine di interventi di by-pass coronarico nelle cardiochirurgie italiane" coordinated by the Italian Institute of Health, and the publication by the news magazine Panorama of the list of the "best" Italian cardiac surgery centres based on a reputational index.The first example points out the problems implied by presenting hospitals' clinical performance through league tables. Using the Markov Chain Monte Carlo method, this study shows how the conclusions merely based on ranking--even when these are based on a sensible quality indicator--can be potentially misleading. As for the second case study, it is shown the inadequacy of the quality indicator (the reputation index) adopted.despite the growing awareness in the health services community of the technical problems implied by describing and comparing the quality of care provided by individual hospitals, "real life" examples of provision of information on quality of care by the mass media to the general public appear to be largely unsatisfactory and potentially misleading.