本文是GRADE（Grading of Recommendations Assessment，Development，and Evaluation）系列文章的导论。该系列文章为使用GRADE系统提供指导，介绍如何将该系统用于系统评价、卫生技术评估（HTAs）及临床实践指南中备选方案的证据质量评价和推荐强度评级。GRADE方法始于提出一个明晰的问题，包括对所有重要结果的详细说明。证据被收集和汇总后，GRADE提供了明确的标准来评价其质量，包括研究设计、偏倚风险、不精确性、不一致性、间接性及效应量大小。
In 2014, the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) working group published guidance in BMJ to evaluate the certainty of the evidence (confidence in evidence, quality of evidence) from network meta-analysis. GRADE working group suggested rating the certainty of direct evidence, indirect evidence, and network evidence, respectively. Recently, GRADE working group has published a series of papers to improve and supplement this approach. This paper introduces the frontiers and advancement of GRADE approach to rate the certainty of evidence from network meta-analysis.
Objective To evaluate the quality of evidence of systematic reviews or meta-analyses regarding outcomes in nursing field in China using the Grade system, so as to get known of the status of the quality of evidence and promote the application of the evaluation of the quality of evidence of systematic reviews. Methods The quality of evidence regarding the included outcomes was input, extracted and qualitatively graded, using GRADEpro 3.6 software. Then, we carefully analyzed and elaborated the factors of downgrading and upgrading that affects the quality of evidence in the process of evaluation. Results 53 systematic reviews or meta-analyses involving 188 outcomes were identified and evaluated. The results showed that high, moderate, low and very low levels of quality of evidence were 2.7%, 27.1%, 51.1%, and 19.1%, respectively; and low-level quality of evidence accounted for the most. Conclusion The quality of evidence produced by systematic reviews or meta-analyses in nursing field in China is poor and urgently needs improvement. The reviewers should abide by the methodological standards in the process of making systematic reviews or meta-analyses. The quality of evidence in terms of each outcome should be evaluated and fully reported.
直接证据来自直接比较我们关注的干预措施用于我们关注的患者人群，并测量患者重要结局的研究。间接证据可由以下4种方式之一产生。第一，患者可能与我们关注的患者不同（适用性一词常用于这类间接性）。第二，所检验的干预措施可能与我们关注的干预措施不同。有关患者和干预措施间接性的决策取决于对生物或社会因素差异是否大到可能使效应尺度出现预期的较大差异的考虑。第三，结果可能有别于最初设定的结局指标——如替代结果本身不重要，但测量之是基于替代结果的变化反映患者重要结局变化这一假设。第四类间接性在概念上与前三类不同，发生于临床医生必须在未经直接比较的两种干预措施间做出选择时。这种情况下比较治疗方案需要特定的统计方法，并根据患者人群、联合干预措施、结局测量指标及备选干预措施试验方法的差异程度，将证据级别降低1或2级。
GRADE方法中，随机试验起评即为高质量证据，观察性研究起评即为低质量证据；但若证据本身存在高发表偏倚风险，则两者证据质量级别都应降低。即使最佳证据汇总表纳入的各项研究仅有低发表偏倚风险，发表偏倚仍会极大高估效应值。当可得证据来自小样本研究、且多数由厂商资助时，作者应怀疑存在发表偏倚。若干基于检验数据类型的方法可用于评价发表偏倚，其中最常用的为漏斗图，但这些方法都有较大局限。发表偏倚可能较常见，必须特别关注早期结果、对样本量与事件数都很小的早期试验结果尤需小心。
ObjectiveTo investigate the recommendations on imaging diagnosis in Chinese clinical practice guidelines (CPGs). MethodsWe electronically searched WanFang Data, VIP, CNKI and CBM databases from inception to December 31, 2014. Two reviewers independently screened literature and extracted data. The method of bibliometrics was used to analyze the data (including basic characteristics, strength of recommendation, quality of evidence, etc.). ResultsA total of 341 CPGs formulating the recommendations on diagnosis were included. 48.7% (166/341) guidelines developed the recommendations on imaging diagnosis (a total of 534). 25.7% (137/534) recommendations were with the symbols of quality of evidence and strength of recommendation, and 18.9% (101/534) with special words such as recommend, suggest. 22.3% (119/534) recommendations reported the strength of recommendation. Of which, 38.7% (46/119) were strong and 16.0% (19/119) were weak. However, 23.9% (11/46) strong recommendations were based on low quality of evidence. And 42.1% (8/19) weak recommendations were based on high quality of evidence. ConclusionAmong Chinese CPGs formulating the recommendations on diagnosis, the number of CPGs with recommendations on imaging is about 50%. And the quantity increases by years. The proportions of recommendations on imaging which report the strength of recommendation and/or quality of evidence are low. Meanwhile, the rating systems are uniform. Then the developers do not report the explanation for the strong recommendations based on low quality of evidence or the weak recommendations based on high quality of evidence in guideline.
Previous methods of grading evidence for systematic reviews of diagnostic test accuracy have generally focused on assessing the certainty (quality) of evidence at the level of diagnostic indicators. When the question is not limited to follow the diagnostic test accuracy results themselves, the grading results may be inaccurate due to the lack of consideration of the downstream effects of the test accuracy in specific settings. To address these challenges, the GRADE working group conducted a series of studies focused on updating methods to explore or simulate important downstream effects of diagnostic test accuracy outcomes within a contextual framework. This paper aimed to introduce advances in the contextual framework of the GRADE approach to rate the certainty of evidence from systematic reviews of single diagnostic test accuracy.
High-quality randomized controlled trials are the best source of evidence to explain the relationship between health interventions and outcomes. However, in cases where they are insufficient, indirect, or inappropriate, researchers may need to include non-randomized studies of interventions to strengthen the evidence body and improve the certainty (quality) of evidence. The latest research from the GRADE working group provides a way for researchers to integrate randomized and non-randomized evidence. The present paper introduced the relevant methods to provide guidance for systematic reviewers, health technology assessors, and guideline developers.
The methodology of conducting systematic review of prognostic studies has received a great deal of interest in recent years. Using GRADE for systematic review of prognostic studies, five aspects should be considered:risk of bias, indirectness, inconsistency, imprecision and publication bias. The methods of using GRADE system in systematic review of prognostic studies are similar to systematic review of interventional studies, meanwhile, there are differences. Not only the uniqueness of prognostic study but also the repeating downgrade should be taken into consideration in the GRADE process. Applying GRADE to systematic review of prognostic studies would be widely accepted along with the methodology development and quality improvement of systematic review of prognostic studies.
GRADE（Grades of Recommendation, Assessment, Development，and Evaluation）方法为卫生保健中的证据质量评价与推荐强度评级提供指导。对那些为系统评价、卫生技术评估及临床实践指南总结证据的人而言，GRADE具有重要意义。GRADE提供了一个系统而透明的框架用以明确问题，确定所关注的结局，总结针对某问题的证据，以及从证据到形成推荐或作出决策。GRADE方法的广泛传播与应用，获全球50余个组织认可，这些组织大多有很强的影响力（http://www.gradeworkinggroup.org/），足以证明该工作的重要性。本文介绍临床流行病学杂志将刊出的20篇系列文章，为如何使用GRADE方法提供指导。