The investigation on the development of medical information research institutions in China and their co-operation showedthat virtual integration model with an additional inscription board and cooperation between local medical academic libraries were the orientation of medical information research institutions in China.Literature novelty assessment, journal edition, network system, website construction, literature and information service, information research service, literature retrieval teaching, user training, health policy management and research, health information statistics were the major tasks of medical information research institutions at present.The recently emerged electronic administrative departments provided a novel visual angle for the cooperation between government organizations , medical information research institutions, and medical libraries.

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.