Extending an evidence hierarchy to include topics other than treatment: revising the Australian 'levels of evidence'

Abstract

BackgroundIn 1999 a four-level hierarchy of evidence was promoted by the National Health and Medical Research Council in Australia. The primary purpose of this hierarchy was to assist with clinical practice guideline development, although it was co-opted for use in systematic literature reviews and health technology assessments. In this hierarchy interventional study designs were ranked according to the likelihood that bias had been eliminated and thus it was not ideal to assess studies that addressed other types of clinical questions. This paper reports on the revision and extension of this evidence hierarchy to enable broader use within existing evidence assessment systems.MethodsA working party identified and assessed empirical evidence, and used a commissioned review of existing evidence assessment schema, to support decision-making regarding revision of the hierarchy. The aim was to retain the existing evidence levels I-IV but increase their relevance for assessing the quality of individual diagnostic accuracy, prognostic, aetiologic and screening studies. Comprehensive public consultation was undertaken and the revised hierarchy was piloted by individual health technology assessment agencies and clinical practice guideline developers. After two and a half years, the hierarchy was again revised and commenced a further 18 month pilot period.ResultsA suitable framework was identified upon which to model the revision. Consistency was maintained in the hierarchy of "levels of evidence" across all types of clinical questions; empirical evidence was used to support the relationship between study design and ranking in the hierarchy wherever possible; and systematic reviews of lower level studies were themselves ascribed a ranking. The impact of ethics on the hierarchy of study designs was acknowledged in the framework, along with a consideration of how harms should be assessed.ConclusionThe revised evidence hierarchy is now widely used and provides a common standard against which to initially judge the likelihood of bias in individual studies evaluating interventional, diagnostic accuracy, prognostic, aetiologic or screening topics. Detailed quality appraisal of these individual studies, as well as grading of the body of evidence to answer each clinical, research or policy question, can then be undertaken as required.

Comparison of Accuracy and Speed of Information Identification by Nonpathologists in Synoptic Reports With Different Formats

“…As previously mentioned, there is an abundance of evidence that mandating and requiring a specific list of elements for inclusion in synoptic reporting, along with the provision of a checklist of those items, can successfully improve the completeness of reports. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] There are also published data concerning the accuracy of the data included in a synoptic report. Specifically, the words no and not are rarely but consistently left off of reports reducing accuracy, and ensuring that the phrases in the checklist contain as few of these elements as possible improves accuracy.…”

“…The CAP specifically requires that each element in a synoptic report be reported in a required data element (RDE) pair consisting of the element and the corresponding response (CAP Laboratory Accreditation Process Checklist question ANP.12385). 1 While there are significant data supporting the use of checklists in general, 2-14 and their use to improve the completeness of surgical pathology reporting specifically, [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] there are much fewer data concerning the significance of the specific formats. Valenstein 34 examined structured reporting and focused on diagnostic headlines, white space, standardized layout, continuity over time, and reduction of clutter but provided few data addressing the specific formats.…”

Vascularized versus Nonvascularized Bone Grafts: What Is the Evidence?

“…The quality of the articles was evaluated using the MINORS scale [43] and National Health and Medical Research Council [NHMRC] Evidence Hierarchy [26]. MINORS ratings ranged from 16 to 18 of 24 (16,16,18,18) and NHMRC Level of Evidence ranged from III-2 (n = 2) to III-3 (n = 2).…”

Data Set for Reporting of Lung Carcinomas: Recommendations From International Collaboration on Cancer Reporting

“…A core (required) element was initially defined as an item of data that was essential for clinical management, staging, or prognostication of the cancer. Core data elements required supporting evidence at level III-2 or above (prognosis category, National Health and Medical Research Council Methodology) 7 and the unanimous support of all members of the panel. A noncore (recommended) element was initially defined as an item of data that was clinically important, recommended as good practice, or regularly used for research purposes or for patient management but which had not, to date, been supported by level III-2 evidence.…”