%0 Journal Article
%T The Swiss cheese model of safety incidents: are there holes in the metaphor?
%A Thomas V Perneger
%J BMC Health Services Research
%D 2005
%I BioMed Central
%R 10.1186/1472-6963-5-71
%X Survey of a volunteer sample of persons who claimed familiarity with the model, recruited at a conference on quality in health care, and on the internet through quality-related websites. The questionnaire proposed several interpretations of components of the Swiss cheese model: a) slice of cheese, b) hole, c) arrow, d) active error, e) how to make the system safer. Eleven interpretations were compatible with this author's interpretation of the model, 12 were not.Eighty five respondents stated that they were very or quite familiar with the model. They gave on average 15.3 (SD 2.3, range 10 to 21) "correct" answers out of 23 (66.5%) ¨C significantly more than 11.5 "correct" answers that would expected by chance (p < 0.001). Respondents gave on average 2.4 "correct" answers regarding the slice of cheese (out of 4), 2.7 "correct" answers about holes (out of 5), 2.8 "correct" answers about the arrow (out of 4), 3.3 "correct" answers about the active error (out of 5), and 4.1 "correct" answers about improving safety (out of 5).The interpretations of specific features of the Swiss cheese model varied considerably among quality and safety professionals. Reaching consensus about concepts of patient safety requires further work.James Reason proposed the image of "Swiss cheese" to explain the occurrence of system failures, such as medical mishaps [1-5]. According to this metaphor, in a complex system, hazards are prevented from causing human losses by a series of barriers. Each barrier has unintended weaknesses, or holes ¨C hence the similarity with Swiss cheese. These weaknesses are inconstant ¨C i.e., the holes open and close at random. When by chance all holes are aligned, the hazard reaches the patient and causes harm (Figure 1). This model draws attention to the health care system, as opposed to the individual, and to randomness, as opposed to deliberate action, in the occurrence of medical errors.The Swiss cheese model is frequently referred to and widely accepted by patien
%U http://www.biomedcentral.com/1472-6963/5/71