AB1052 Qualitative systematic review: lack of consensus on the classification criteria for diffuse idiopathic skeletal hyperostosis
Authors: JS Kuperus, EE de Gendt, FC Oner, PA de Jong, SC Buckens, AE van der Merwe, GJ Maat, EA Regan, D Resnick, R Mader, J-J Verlaan
Journal: Annals of the Rheumatic Diseases (2017)

<h3>Background</h3> Diffuse idiopathic skeletal hyperostosis (DISH) is a condition characterized by flowing ossifications of the spine with or without ossifications of entheses elsewhere in the body.<sup>1,2</sup> Studies on prevalence and pathogenesis of DISH use a variety of partially overlapping combinations of classification criteria, making meaningful comparisons across the literature difficult.<sup>3,4</sup> <h3>Objectives</h3> The aim of this study was to systematically summarize the criteria available to classify or diagnose DISH to aid in the development of a more uniform set of diagnostic and/or classification criteria. <h3>Methods</h3> A search was performed in Pubmed, Embase, Cochrane Library and Web of Science using the term DISH and its synonyms. Articles were included when two independent observers agreed that the articles proposed a new set of classification criteria for DISH. All retrieved articles were evaluated for methodological quality and the presented criteria were extracted. The criteria were placed into one of three groups being "descriptive studies", "sets of criteria for dichotomous diagnosis" or "sets of criteria with consecutive phases". <h3>Results</h3> A total of 24 articles met the inclusion criteria. Two articles were descriptive studies, 11 contained dichotomous classification criteria and 11 described a set of criteria with consecutive phases. In all articles spinal hyperostosis was required for the diagnosis of DISH. Peripheral, extraspinal manifestations were included as a (co-)requirement for the diagnosis DISH in five articles. Most discrepancies revolved around the threshold for the number of vertebral bodies affected and to defining different developmental phases of DISH. More than half of the retrieved articles described a dichotomous set of criteria and did not consider the progressive character of DISH. <h3>Conclusions</h3> In our systematic review we summarize the available different classification criteria for DISH and highlight the lack of consensus on the diagnosis of (early) DISH. Consensus criteria, including consecutive phases of new bone formation that characterize DISH can be developed based upon established diagnostic and/or classification criteria. <h3>References</h3> Resnick D, Niwayama G. Radiographic and pathologic features of spinal involvement in diffuse idiopathic skeletal hyperostosis (DISH). Radiology. 1976;119(3):559–568. Mader R, Verlaan J, Buskila D. Diffuse idiopathic skeletal hyperostosis: clinical features and pathogenic mechanisms. Nat Rev Rheumatol. 2013;9(12):741–750. Pillai S, Littlejohn G. Metabolic factors in diffuse idiopathic skeletal hyperostosis - a review of clinical data. Open Rheumatol J. 2014;8(1):116–128. Mader R, Buskila D, Verlaan J-J, et al. Developing new classification criteria for diffuse idiopathic skeletal hyperostosis: back to square one. Rheumatology (Oxford). 2013;52(2):326–330. <h3>Acknowledgements</h3> None. <h3>Disclosure of Interest</h3> None declared