1.Comparison of simple pooling and bivariate model used in meta-analyses of diagnos-tic test accuracy published in Chinese journals
Yuansheng HUANG ; Zhirong YANG ; Siyan ZHAN
Journal of Peking University(Health Sciences) 2015;(3):483-488
Objective:To investigate the use of simple pooling and bivariate model in meta-analyses of diagnostic test accuracy (DTA) published in Chinese journals (January to November, 2014), compare the differences of results from these two models, and explore the impact of between-study variability of sensitivity and specificity on the differences. Methods:DTA meta-analyses were searched through Chi-nese Biomedical Literature Database (January to November, 2014). Details in models and data for four-fold table were extracted. Descriptive analysis was conducted to investigate the prevalence of the use of simple pooling method and bivariate model in the included literature. Data were re-analyzed with the two models respectively. Differences in the results were examined by Wilcoxon signed rank test. How the re-sults differences were affected by between-study variability of sensitivity and specificity, expressed by I2 , was explored. Results:The 55 systematic reviews, containing 58 DTA meta-analyses, were included and 25 DTA meta-analyses were eligible for re-analysis. Simple pooling was used in 50 (90. 9%) systematic reviews and bivariate model in 1 (1. 8%). The remaining 4 (7. 3%) articles used other models pooling sensitivity and specificity or pooled neither of them. Of the reviews simply pooling sensitivity and specificity, 41(82. 0%) were at the risk of wrongly using Meta-disc software. The differences in medians of sensitivity and specificity between two models were both 0. 011( P<0. 001, P=0. 031 respectively). Greater differences could be found as I2 of sensitivity or specificity became larger, especially when I2 >75%. Conclusion:Most DTA meta-analyses published in Chinese journals(January to November, 2014) combine the sensitivity and specificity by simple pooling. Meta-disc software can pool the sensitivity and specificity only through fixed-effect model, but a high proportion of authors think it can implement random-effect model. Simple pooling tends to underestimate the results compared with bivariate model. The greater the between-study variance is, the more likely the simple pooling has larger deviation. It is necessary to increase the knowledge level of statistical methods and software for meta-analyses of DTA data.
2.TRANSFER OF TAEKYPLEUS TRICLENTENTUS HEMOCYANIN(TTH)AND DNP-BSA DERMAL REACTIVITY TO HUMAN WITH GOOSE DERIVED TRANSFER FACTOR
Yuansheng ZHAN ; ET AL ;
Chinese Journal of Immunology 1986;0(04):-
TTH and DNP-BSA delayed hyper-sensitivity(DH)were transfered tononimmune human recipients withGoose derived transfer factor(TF-G)prepared from blood and spleen ofGoose immunized with TTH or DNP-BSA.Only human recipients injec—ted with immune TF-G showed DHskin reactivity by skin test.TTHDH response were only transferedby TTH specific TF-G but not DNPBSA specific TF-G and the DNP-BSAdermal reactivity could only be ob-served when DNP-BSA specific TF-G were employed.The fact that TF-G was able to tranfer donor specificDTH to human recipients suggestedthat there may be no absolute speciesbarriers for DTH transfer with TF.

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