Rhinosinusitis is a significant health problem which seems to mirror the increasing frequency of allergic rhinitis and which results in a large financial burden on society (1) . The last decade has seen the development of a number of guidelines, consensus documents and position papers on the epidemiology, diagnosis and treatment of rhinosinusitis and nasal polyposis (1-6). In 2005 the first European Position Paper on Rhinosinusitis and Nasal Polyps (EP3 OS) was published (4, 7). This first evidence based position paper was initiated by the European Academy of Allergology and Clinical Immunology (EAACI) to consider what was known about rhinosinusitis and nasal polyps, to offer evidence based recommendations on diagnosis and treatment, and to consider how we could make progress with research in this area. The paper was endorsed by the European Rhinologic Society. Such was the interest in the topic and the increasing number of publications that by 2007 we felt it necessary to update the document: EP3 OS2007 (1, 5). These new publications included some important randomized controlled trials and filled in some of the gaps in our knowledge, which has significantly altered our approach. In particular it has played an important role in the understanding of the management of ARS and has helped to minimize unnecessary use of radiological investigations, overuse of antibiotics, and improve the under utilisation of nasal corticosteroids (8). EP3 OS2007 has had a considerable impact all over the world but as expected with time, many people have requested that we revise it, as once again a wealth of new data has become available in the intervening period. Indeed one of its most important roles has been in the identification of the gaps in the evidence and stimulating colleagues to fill these with high quality studies. The methodology for EPOS2012 has been the same as for the other two productions. Leaders in the field were invited to critically appraise the literature and write a report on a subject assigned to them. All contributions were distributed before the meeting in November when the group came together in Amsterdam and during the 4 days of the meeting every report was discussed in detail. In addition general discussions on important dilemmas and controversies took place. Finally the management schemes were revised significantly in the light of any new data which was available. Finally we decided to remove the "3" out of EPOS2012 title (EPOS212 instead of EP3 OS2012) to make it more easy to reproduce. Evidence based medicine is an important method of preparing guidelines. In 1998 the Centre for Evidence Based Medicine (CEBM) published its levels of evidence, which were designed to help clinicians and decision makers to make the most out of the available literature. Recently the levels of evidence were revised in the light of new concepts and data (Table 1). Moreover a number of other systems which grade the quality of evidence and strength of recommendation have been proposed. The most important of these is probably the GRADE initiative (9). For the EPOS2012 we have chosen to collect the evidence using the orginal CEBM format but we plan to update the EPOS2012 clinical recommendations subsequently, following the approach suggested by the GRADE working group
This EPOS 2012 revision is intended to be a state-of-the art review for the specialist as well as for the general practitioner:
  • to update their knowledge of rhinosinusitis and nasal poly-posis;
  • to provide an evidence based review of the diagnostic methods;
  • to provide an evidence-based review of the available treatments;
  • to propose a stepwise approach to the management of the disease;
  • to propose guidance for definitions and outcome measurements in research in different settings.
Overall the document has been made more consistent, some chapters are significantly extended and others are added. Last but not least contributions from many other part of the world have increased our knowledge and understanding. One of the important new data acquired in the last year is that on the prevalence of CRS in Europe. Previously we had relied on estimates from the USA pointing at a prevalence of 14%. Firstly the EPOS epidemiological criteria for CRS from the 2007 document were validated. We have shown that the EPOS symptom-based definition of CRS for epidemiological research has a moderate reliability over time, is stable between study centres, is not influenced by the presence of allergic rhinitis, and is suitable for the assessment of geographic variation in prevalence of CRS (11). Secondly, a large epidemiological study was performed within the GA(2)LEN network of excellence in 19 centres in 12 countries, encompassing more than 50.000 respondents, in which the EPOS criteria were applied to estimate variation in the prevalence of Chronic rhinosinusitis for Europe. The overall prevalence of CRS was 10.9% with marked geographical variation (range 6.9-27.1) (12). There was a strong association of asthma with CRS at all ages and this association with asthma was stronger in those reporting both CRS and allergic rhinitis (adjusted OR: 11.85). CRS in the absence of nasal allergies was positively associated with late-onset asthma (13). In the EPOS2012 we have made a stricter division between CRS with (CRSwNP) and without nasal polyps (CRSsNP) (14). Although there is a considerable overlap between these two forms of CRS in inflammatory profile, clinical presentation and effect of treatment (1, 15-20) there are recent papers pointing to differences in the respective inflammatory profiles (21-26) and treatment outcome (27). For that reason management chapters are now divided in ARS, CRSsNP and CRSwNP. In addition the chapters on acute and chronic paediatric rhinosinusitis are totally revised and all the new evidence is implemented. We sincerely hope that EPOS will continue to act as a stimulus for continued high quality clinical management and research in this common but difficult range of inflammatory conditions.