[Masks as personal protective equipment in the COVID-19 pandemic: How, when and which should be used].

Background And Objective: In the COVID-19 pandemic, the demand of masks has been increased by health professionals and the general population. In this context, it is necessary to summarize the features and indications of the different types of masks.

Material And Methods: To consult and to compile the different recommendations disseminated by prestigious institutions such as the World Health Organization, the European Center for Disease Prevention, the Center for Evidence-Based Medicine, or the Ministry of Health of the Government of Spain has been reviewed.

Should policy-makers and managers trust PSI? An empirical validation study of five patient safety indicators in a national health service.

Background: Patient Safety Indicators (PSI) are being modestly used in Spain, somewhat due to concerns on their empirical properties. This paper provides evidence by answering three questions: a) Are PSI differences across hospitals systematic -rather than random?; b) Do PSI measure differences among hospital-providers -as opposed to differences among patients?; and, c) Are measurements able to detect hospitals with a higher than "expected" number of cases?

Methods: An empirical validation study on administrative data was carried out. All 2005 and 2006 publicly-funded hospital discharges were used to retrieve eligible cases of five PSI: Death in low-mortality DRGs (MLM); decubitus ulcer (DU); postoperative pulmonary embolism or deep-vein thrombosis (PE-DVT); catheter-related infections (CRI), and postoperative sepsis (PS).