[Umbrella review - a new method related to evidence-based medical analysis].

Umbrella review is a newly developed method, used for evidence-based medicine analysis. It is somehow better than systematic reviews and Meta-analysis for medical evidence analysis. It is based on systematic reviews and Meta-analysis but in a more sophisticate way. In many specific occasions, it is similar to Meta-analysis but with more uniqueness. This paper introduces and focusing on the concept, major steps of operation, limitations and developing trends of the umbrella review.伞形评价是一种最新的循证医学分析方法，是继系统评价和Meta分析之后的更高层级的医疗证据分析方法。它以系统评价和Meta分析为基础，又高于系统评价和Meta分析。所以在很多具体操作方面，它与Meta分析类似，但更需要注意其独特之处。本文着重介绍了伞形评价的概念、主要步骤、局限性以及发展趋势等。.