Baird A Gordon, Lawrence James R
Research and Development Support Unit, Dumfries and Galloway Royal infirmary, Dumfries, Scotland, UK.
BMJ Open. 2014 Feb 5;4(2):e004278. doi: 10.1136/bmjopen-2013-004278.
To quantify and analyse the quality of evidence that is presented in national guidelines.
Levels of evidence used in all the current valid recommendations in the Scottish Intercollegiate Guideline Network (SIGN) guidelines were reviewed and statistically analysed.
The proportion of level D evidence used in each guideline and a statistical analysis.
Data were collected from published guidelines available online to the public. SIGN methodology entails a professional group selected by a national organisation to develop each of these guidelines. Statistical analysis of the relationship between the number of guideline recommendations and the quality of evidence used in its recommendations was performed.
The proportion of level D evidence increases with the number of recommendations made. This correlation is significant with Kendall's τ=0.22 (approximate 95% CI 0.008 to 0.45), p = 0.04; and Spearman ρ=0.22 (approximate 95% CI 0.02 to 0.57), p=0.04.
Practice guidelines should be brief and based on scientific evidence. Paradoxically the longest guidelines have the highest proportion of recommendations based on the lowest level of evidence. Guideline developers should be more aware of the need for brevity and a stricter application of evidence-based principles could achieve this. The findings support calls for a review of how evidence is used and presented in guidelines.
对国家指南中所呈现的证据质量进行量化和分析。
对苏格兰校际指南网络（SIGN）指南中所有当前有效推荐所使用的证据级别进行审查并进行统计分析。
每条指南中使用的D级证据比例以及一项统计分析。
从向公众在线发布的已发表指南中收集数据。SIGN方法要求由一个国家组织挑选一个专业小组来制定每条指南。对指南推荐数量与其推荐中所使用证据质量之间的关系进行统计分析。
D级证据的比例随着所做推荐数量的增加而上升。这种相关性具有显著性，肯德尔τ系数为0.22（近似95%置信区间0.008至0.45），p = 0.04；斯皮尔曼ρ系数为0.22（近似95%置信区间0.02至0.57），p = 0.04。
实践指南应简洁并基于科学证据。矛盾的是，最长的指南基于最低级别证据的推荐比例最高。指南制定者应更加意识到简洁的必要性，更严格地应用循证原则可实现这一点。这些发现支持对指南中证据的使用和呈现方式进行审查的呼吁。
