第2讲 循证医学的证据来源和检索打印版

(Sackett et al. BMJ 1996).
E4 BM，循证医学（Evidence based Medicine）：
是临床医生经过认真尽责地、正确判断地且很明确 地做出决定：将最佳证据应用于临床实践诊治病人 以便于取得最佳诊疗效果。
EBM
The thinking behind evidence-based medicine is very soundly based on Clinical Epidemiology;
American College of Physicians Journal Club
Evidence-based Medicine
Scientific reports/ Government reports. For example:
National Health and Medical Research Council Health Advisory Committee
医学期刊是循证医学最重要的源泉
29 国内外际上有数以万计的医学期刊。 循证医学，需要学会快速地检索和获取医学期刊文献。 通过互联网络检索是最快获取资料的方法之一，有许多检索
方法和网址，其中较常用的之一是美国国家生物学技术信息 中心的PubMed网页 从互联网络上所能获得的文献的原文是很有限的，图书馆中 的期刊是循证医学的源泉。 在获得所需要的文章以后，还要运用临床流行病学的方法判 断该研究的可靠性和有效性。
6. Therapy （治疗）: how to select treatments to offer the patients that do more good than harm and that are worth the efforts and costs of using them.
Eight central tasks of clinical work that generate clinical questions:
development.
EBM
Three components of EBM
Evidence
EBM
Clinician
Patient
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四大因素的有机结合 临床流行病学方法学基础
最佳 研究 成果
素质 良好 医师
患者的参与
循证医学
STEPS IN EBM
Evidence-based Medicine starts with a well-defined clinical problem and then seeks best evidence to solve this problem for the individual patient’s situation.
Eight central tasks of clinical work that generate clinical questions:
1. 临床结果（Clinical findings）: 怎样恰当地采集病 史，并根据病史和身体检查来解释临床结果 。（how to properly gather and interpret findings from the history and physical examination.）
to complement clinical expertise in providing best care for patients;
to make best, rational, use of limited resources; as an aid to continuing education and professional
What is new is the enormous and growing capacity to access knowledge in an efficient manner.
Evidence-based medicine exploits the information explosion that might otherwise overwhelm us.
Step 2 - Searching for Evidence
Having framed your question, the next step is to identify sources of information. These might include:
Textbooks Journals and Newsletters. For example:
Cochrane Library：每年四期，
中文生物医学文献数据库（CBM）：中国医学科 学院医学信息研究所研制
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Search for Primary Sources
and the practice will be familiar to those of you who have experience of problem-based learning.
EBM
The philosophy of evidence-based medicine is not new.
2. 病因学（Etiology）: 怎样来识别或鉴定病因 （how to identify causes for disease (including its iatrogenic forms， 医源性的)）？
Eight central tasks of clinical work that generate clinical questions:
Step 2 - Searching for Evidence
Guidelines. For example:
The United States Preventive Services Task Force - Guide to Clinical Preventive Services
EMJA Clinical Guidelines
There are four main steps:
STEPS IN EBM
1. Framing Clinical Questions.
2. Searching for Evidence.
3. Appraising the Evidence.
4. Applying the Evidence.
12复习： 怎么构架问题？或者都有哪些问题需要来回答 的？
Step 1 - Framing Clinical Questions
询证医学的第一步是问正确的临床问题：这些有 关患者保健问题都是医生每天所要面对的。
如何解释这些临床结果? 哪些诊断试验有助于诊断和管理病人? 哪些治疗将会带来最大的“风险与获益”比? 预后是怎样的?
Step 1 - Framing Clinical Questions
Eight central tasks of clinical work that generate clinical questions:
5. Prognosis （预后）: how to estimate the patient’s likely clinical course over time and anticipate likely complications of the disease.
因为许多临床的问题，难以从教科书中找到令人满意的解答。 各个层次的教科书一般来说已经成熟的理理论外，多有作者比较成熟的经验和 观点。 对于全科医生和低年资的专科医生，教科书和专著往往是循证的重要 途径。即使是高年资的专科医生，也常常需要浏览教科书和专著，以 较全面地了解本学科的总体发展。 对于特殊临床问题的循证，往往需要从后面几个角度去寻找外部的证 据。
DARE
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循证医学实践的步骤
27检索相关文献
根据提出的临床问题，确定“检索词” 利用各种权威的检索系统检索相关文献。 从检索结果中找出与问题关系密切的资料，作为分析
评价之用。 文献检索只是循证医学实践中的一个环节。
寻找外部证据的途径
28 教科书与专著：从教科书与专著循证是传统的方法，但不是最佳的方 法。
Databases. For example:
Cochrane Library Best Evidence
Bibliographic databases. For example:
Medline EMBASE
Other internet sources. For example:
The skills being to ask the right questions, look for answers, and interpret and apply those answers for the best health outcomes.
EBM
Evidence-based medicine is a tool with many applications:
3. Differential diagnosis （鉴别诊断）: when considering the possible causes of a patient’s clinical problem, how to rank them by likelihood, seriousness and treatability.
30 一次文献：专著，期刊论文，科技报告，学位论文。
二次文献：索引，文摘，目录，相应的数据库。
三次文献：综述，评述，进展，现状，发展趋势等期 刊文献和百科全书，年鉴，手册等参考工具书。
零次文献：实验数据，观测记录，调查材料。
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33 PubMed：美国国立医学图书馆创建，收集全球70 多 个 国 家 和 地 区 3900 余 种 杂 志 ， Evidence-Based Medicine是主题词（MeSH Term） http://ncbi.nlm.nih.gve/PubMed