CommentaryRecommendation without experts? Epistemological implications in the development of screening guidelines

- The controversies on the interpretation and assessment of prevention trials continue.
- Excluding content experts from systematic reviews has been attempted to avoid controversies and conflicts of interest.
- This approach ignores the role of conjectures in assessing evidence.
- Conjectures are necessary for producing knowledge and even for assessing evidence.

Controversies concerning mammographic and cervical cancer screening with HPV-DNA recommendations lead to an analysis of the role played by a knowledge of disease epidemiology, natural history and pathogenesis in producing sound recommendations.This analysis calls into question the decision to exclude experts on the specific topic from guideline and recommendation development because such experts may bring prejudices or even conflicts of interest to the debate. According to this approach, methodology is the only factor that guarantees the soundness of evidence assessment. The assumption underlying such an epistemological point of view is that evidence is “absolute,” i.e. not linked to any interpretative model or conjecture. Actually, any form of scientific knowledge includes conjectures, which by definition are not demonstrable, in order to interpret evidence. Even as we assess evidence, we need to select or formulate conjectures that explain most of the evidence available. In order to decide on such conjectures, we require individuals who are familiar with the epidemiology and the aetiology of the disease, as well as with the rationale behind the technologies or interventions proposed. Finally, we need individuals who know the strengths and the weaknesses of alternative conjectures; in other words, we also require content experts.