Discordant and inappropriate discordant recommendations in consensus and evidence based guidelines: empirical analysis
This analysis found that in the face of low quality evidence, consensus-based guidelines were more likely to issue strong recommendations (discordant recommendations) and to issue inappropriate discordant recommendations than guidelines categorised as evidence-based.
Source:
British Medical Journal
SPS commentary:
In this research, the authors carried out an empirical assessment of how often consensus versus evidence based guidelines issued strong recommendations based on low quality evidence (discordant) and how many of them are inappropriate (inappropriate discordant recommendations). They focused on guidelines developed by the American College of Cardiology and the American Heart Association (ACC/AHA) and the American Society of Clinical Oncology (ASCO). These organisations use their own grading systems when developing practice guidelines.
Although there are some exceptions to the rule, in general there should be concordance between quality of evidence and strength of recommendations, and the failure to ensure this violates a key principle of evidence based medicine and risks misleading guidance. In this study, ACC/AHA and ASCO were found to produce overall 41% and 20% inappropriate and probably harmful recommendations based on low quality evidence; when they use consensus rather than evidence based methods they have 2.6 and 5.1 times greater odds of issuing inappropriate discordant recommendations, respectively.
The authors say their findings raise serious concerns, noting that strong recommendations based on low or very low-quality evidence are seldom appropriate, and that this might lead to patients receiving interventions for which the benefits do no clearly outweigh the harms. They conclude their results “support re-examining the wisdom of developing consensus based guidelines, and promoting enhanced rigour to ensure, whatever label the recommendations are given, appropriate alignment of quality of evidence with strength of recommendations.”
A linked opinion article notes that classifying guidelines as consensus based might allow panels to be less rigorous in ensuring that the strength of recommendations are consistent with the underlying quality of evidence, and consider that abandoning consensus based guidelines is likely to help in the avoidance of inappropriate discordant recommendations.