The Semmelweis Framework: Structuring Evidence Foundations and Expert Opinion in Clinical Practice Guidelines
Blin Nagavci
KÁROLY RÁCZ CONSERVATIVE MEDICINE PROGRAM
Dr. Fekete Andrea
SE NET Orálbiológiai Tanszék, könyvtár
2026-10-22 14:00:00
Clinical Haematology
Dr. Masszi Tamás
Dr. Lakatos Botond Tibor
Dr. Peskó Gergely
Dr. Klemencsics István
Dr. Kocsis Béla
Dr. Ostorházi Eszter
Dr. Boga Márton
Clinical practice guidelines are usually developed using the best available evidence from systematic reviews and formal evidence appraisal. However, in many areas of medicine, evidence is limited, indirect, inconclusive, or completely absent. In such situations, guideline panels often rely on expert opinion to issue clinically useful recommendations. Despite its frequent use, expert opinion remains poorly defined and inconsistently presented in guideline methodology. This thesis addressed this methodological gap by examining how expert opinion is used, how it is defined, and how it can be integrated more transparently into clinical guideline development.
The thesis consisted of three linked work packages. The first work package analysed the use of expert opinion in international infectious diseases guidelines. It showed that expert opinion is commonly used, but with substantial variation in terminology, reporting, and methodological transparency. These findings highlighted the need for a more structured and transparent approach.
The second work package examined methodological manuals from guideline-developing organisations across different medical fields. This analysis showed that expert opinion is mainly used for two purposes: to fill evidence gaps when direct evidence is unavailable, and to interpret evidence when it is weak, indirect, or inconclusive. Based on this work, a new definition of expert opinion was proposed. The concept was defined as guidance derived from clinical experience, expert judgement, indirect evidence, very low-quality evidence, or mechanism-based reasoning, aimed at supporting clinical decision-making when evidence is absent or requires contextual interpretation.
The main output of the thesis is the Semmelweis Framework, developed in the third work package. The Framework provides a structured method for classifying clinical recommendations according to their evidentiary foundation. It defines four classes of recommendations: recommendations based on direct evidence, indirect evidence, non-comparative evidence, and expert judgement. As the evidence becomes weaker, less direct, or absent, the role of expert opinion progressively increases. The Framework also introduces standardised labels, clear recommendation wording, and a mandatory Preconditions Checklist for recommendations relying on weaker foundations.
