Article Text
Abstract
Background Development of guidelines for medical tests are challenging given the indirectness of evidence on patient outcomes. We compared grading systems for medical tests in terms of basic guideline quality requirements and on how they use indirect evidence.
Methods We used a systematic search to identify grading systems specific to medical tests in PubMed, professional guideline websites and handsearching back references of key articles. Using the AGREE instrument as a starting point, we defined two sets of characteristics to describe these systems: process and methodological ones. Process characteristics were features related to the guideline development process. Methodological characteristics were defined as features relating to how evidence is gathered, appraised and recommendations development. Data was extracted in duplicate and differences resolved through discussion.
Results Twelve grading systems were included. Process characteristics least often addressed were whether the system was piloted (3/12) and funder information (3/12). Methodologically, developing a clinical scenario, care pathway and/or analytical framework, having explicit criteria for appraising and linking indirect evidence, and having explicit methodologies for translating evidence into recommendations were least frequently addressed. Five systems at most addressed these to varying degrees of completeness.
Implications for Guideline Developers There is a need for standardisation of basic guideline features a grading system should address. No one system adequately addressed the complexity of gathering, assessing and linking different bodies of evidence. There is a need for critical appraisal of these features in each system and for targeted user testing among guideline developers.