Evidence is the core of Evidence-Based Medcine; the Grades of Recommendations Assessment, Development and Evaluation (GRADE System) is a milestone in the history of evidence development. This paper outlines the GRADE System and GRADEpro 3.2 software, and briefly explores the right and wrong application which was published in the Chinese Journal of Evidence-Based Medicine. The GRADEpro 3.2 software is easy to operate, but for evaluating the reasons of upgrade and downgrade, and the importance of the parameters of outcomes, it needs to comprehensively and systematically understand the knowledge of relevant background, and to construct a solid foundation in clinical epidemiology and systematic review. In view of this paper based on the current GRADE System, there may be some discrepancy to the later content with the GRADE System constant improvement. Therefore, it is bly recommended that readers should keep constant learning and improving.
Objective To evaluate the efficacy and safety of acellular dermal matrix (ADM) in preventing Frey syndrome.Methods Studies of acellular dermal matrix in preventing Frey syndrome were searched in The Cochrane Library (Issue 1, 2010), MEDLINE, EMbase, SIGLE, GreyNet, NTIS, CBMdisc, VIP, CNKI and WANFANG DATA from 1995 to 2010. All the studies were selected, extracted and evaluated by four reviewers independently, and meta-analyses were performed with RevMan 5.0.0 software. Results A total of 15 studies involving 472 participants were included in the review. The studies showed that implantation of the ADM was able to efficiently reduce the incidence of Frey syndrome, and the difference in both subjective and objective was significant between the two groups after the therapy (RR=0.11, 95%CI 0.06 to 0.18, Plt;0.01; RR=0.14, 95%CI 0.10 to 0.19, Plt;0.01). The rate of temporary facial nerve paralysis was lower than that of the control group but the difference was not significant (OR=0.78, 95%CI 0.37 to 1.66, P=0.53). The incidens of both seroma and mucocele were higher than that of the control group but the difference was not significant(OR=2.63, 95%CI 0.09 to 79.25, P=0.58) and they could be alleviated by placing drainage tube and partial pressure bandage. The incidence rate of salivary fistula was lower than that of the control group and the difference was significant (OR=0.24, 95%CI 0.08 to 0.69, P=0.009). Conclusion The result of this system review shows that, the ADM can effectively and safely reduce the incidence of Frey syndrome. To perform preoperative hypersensitivity check for iodine or iodophors, to conduct rapid frozen section for defining the character of tumor, to fix the ADM stably, to place vacuum-drainage and to make partial pressure bandage are suggested.