Preferred Reporting Items for Diagnostic Accuracy Studies in Endodontics (PRIDASE): Guidance to improve manuscripts assessing the diagnostic accuracy of procedures, techniques and devices

For centuries, diagnosis in Medicine and Dentistry has been considered more of an art than a science, an intuitive skill that could only be mastered by experienced clinicians. Indeed, it was considered impossible to develop standardized, practical, operationalized diagnostic criteria. Understanding of the cognitive processes underlying diagnostic procedures has improved recently, and it is now recognized that rather than being mysterious, diagnostic proficiency is dependent largely on nonanalytic pattern recognition (Loveday et al., 2013). This recognition is a product of practice and reflection, often largely subconscious, relating to feedback from earlier clinical trials. Not surprisingly, experience brings increased confidence and efficiency, but reliable schemebased analytic strategies can also be learned by beginners (Coderre et al., 2003), which is helpful when teaching students how to approach the complex task of diagnostics. Diagnostic algorithms based on commonly agreed disease definitions and operationalized diagnostic criteria are highly successful to correctly identify disease. In Medicine, this is a major step forward as agreement on standardized diagnostic procedures has the potential to vastly improve research possibilities, similar to the way experimental interventions to treat disease follow strict methodological protocols in randomized clinical trials. That said, this approach is not without controversy, as differences in opinion remain on the exact characteristics of a certain condition, and also on the best approach to identify it. Endodontics is struggling with the same issues. The endodontic diagnostic nomenclature, debated for many years, is ambiguous and lacks global consensus on specific criteria for common endodontic disorders. For example, the term irreversible pulpitis should mean that the level of pulp inflammation is such that pulp necrosis is inevitable and complete removal by pulpectomy or extraction is the only prescribed therapy. Currently, the term is generally used simply as a clinical description of a set of specific signs and symptoms assumed to represent a severe state of inflammation in the entire pulp, which in reality does not necessarily reflect the differing levels of inflammation that may exist between the superficial (pulp horns) and deep (radicular) portions of the pulp. A comprehensive systematic review concluded that the scientific evidence is insufficient to determine if symptoms and signs (such as the presence, character and persistence of toothache) and response to stimuli (such as a heightened response to pulp sensibility testing or thermal provocation) can provide valid information about the true (histopathological) pulp status (Mejare et al., 2012). This would suggest that many pulps diagnosed as irreversibly inflamed could be managed conservatively and vice versa. On a clinical level, this may lead to systematic overtreatment (unnecessary root canal treatment [RCT]), and although the prognosis of RCT is good, unnecessary RCTs should be avoided, with data on a population basis indicating that about one tooth in ten is extracted within 5– 6 years after RCT (Fransson et al., 2016). In addition, indiscriminate labelling of pulpitis as irreversible may lead to a lack of research focused on the development of innovative therapies for pulp preservation or on improved pulp diagnostics. These are compelling reasons why diagnostics need to be as accurate and precise as possible, and in order to achieve this, studies investigating diagnostic accuracy need to be methodologically robust and meticulously reported. It is likely that the lack of consensus between experts, clinicians and researchers is caused by a lack of evidence. To address this, endodontic researchers must start by collecting the necessary data systematically. One potential way forward is to identify a reliable diagnostic algorithm, similar to those in other medical areas. An example from Dentistry is the Diagnostic Criteria for Temporomandibular Disorders (DCTMD) for painrelated diagnoses. Using a specific combination of anamnestic findings (the history) and clinical examinations, it is possible to correctly identify 80– 86% of cases and 97– 98% of non-cases with an interexaminer reliability of ≥85% (Schiffman et al., 2014). However, this is not straightforward; a prerequisite for building a diagnostic