Endocrine Abstracts

Evidence-based clinical guidelines in Endocrinology attempt to improve and standardise patient care. There has been an expansion in guideline production although some of the heterogeneous methods used to assess the underlying evidence base may limit interpretation and implementation. Current and archived guidelines from The American Association of Clinical Endocrinologists (AACE), The Endocrine Society (ES), The American Thyroid Association, The British Thyroid Association and The Society for Endocrinology were accessed. 29 guidelines from 1995–2011 that documented the evidence level for each recommendation were analysed. To allow comparison, evidence levels within guidelines were standardised into three categories: “high” based on randomised-controlled trials and meta-analyses, “moderate” based on non-randomised studies and “low” on expert opinion. The organisations used six different methods to rate underlying evidence including, Grading of Recommendations Assessment, Development and Evaluation (GRADE). Guideline production increased with time (1995–2000=9, 2001–2005=12, 2006–2011=36). Three guidelines were updated with an average delay of 4.3 years and an increase in recommendations per guideline (21.1%). Encouragingly, whilst updates had similar levels of “high” quality evidence, there was increased reliance on “moderate” category evidence and less on “low” quality evidence (“high” 6.3% vs 6.5%, “moderate” 46.1% vs 59.1% and “low” 47.7% vs 34.4%). AACE and ES produced most guidance and had comparable strengths of underlying evidence (“high”=14.1% vs 15.8%, “moderate” 49.9% vs 43.4% and “low”=36% vs 40.7%; from 702 vs 298 recommendations). A high proportion of “low” category evidence was seen across organisations. Rarer conditions and recommendations concerning treatment efficacy were particularly reliant on “low” category evidence. The level of evidence underpinning guidance highlights areas in need of well-designed, collaborative clinical research. Furthermore, criteria to define when guideline updates are necessary are currently lacking. A standardised method of assessment, such as GRADE, would promote understanding and compliance by guideline users with the ultimate aim of enhancing patient care.

Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.