In this paper, we introduce meaning and purpose of confidence interval (CI) in evidence-based medicine, For example, RRR ,ARR ,NNT. It s referance for user and doer of EBM in China.
To show that a new drug is better than, as good as, or no worse than that of a known effective drug. Theoretically, it is necessary to confirm the efficacy of a treatment, but the current practice of clinical trial suggests that there exists many problems in its confirmation including the objectives of clinical investigation vary based on the fact that more and more clinical trials use active controls. Applied statistical methods have to adapt to these changes. In this paper, we illustrated some statistical issues of confirming efficacy in clinical trials, including its conditions, the determination of clinical margin, the forms of the null and alternative hypothesis and confidence intervals, the choice of endpoints and some miscellaneous considerations. We bly suggests that it is necessary to make biostatisticians and clinical trialists understand the importance of using the right statistical methods when investigating clinical trials. We also think these methods introduced in the paper may provide some help in trial design and evaluation.
目前,新型农村合作医疗正在我国300多个县(市)开展试点工作.然而,在农村总体经济实力不强又面临市场经济冲击的大形势下,建立新型农村合作医疗制度将是一项十分艰难、复杂的工程.本文讨论了新型农村合作医疗制度产生的历史背景及如何增强农民对新型农村合作医疗制度的信心问题.
Objective To investigate the value of the multi-detector row spiral CT (MDCT) and 3-dimensional reconstruction technique for adult intussusception. Methods Twenty-one patients with surgically and clinical following-up confirmed intussusception were retrospectively included into this study. Three patients had plain MDCT scan, 18 received contrast enhanced MDCT scan. The original images were reconstructed with multi-planar reconstruction (MPR) technique and all the images of 21 patients were divided into original image group and original image add MPR image group. Two abdominal radiologists analyzed the MDCT imaging and recorded respectively the accuracy rate and the confidence index of the doctor about following indexes: whether or not having intussusception, the location of intussusception, finding reason caused intussusception, whether or not having bowel wall ischemia and whether or not having bowel obstruction. The accuracy rate and the confidence index of the doctor were compared using a SPSS statistics software. Results The accuracy rates about above indexes between original image group and original image add MPR image group were 90.5% (19/21) vs. 100% (21/21), 81.0% (17/21) vs. 95.2% (20/21), 85.7% (18/21) vs. 90.5% (19/21), 90.9% (10/11) vs. 90.9% (10/11) and 100% (11/11) vs. 100% (11/11) respectively, and there was no significant difference between original image group and original image add MPR image group (Pgt;0.05). For following indexes: whether or not having intussusception, the location of intussusception, finding reason caused intussusception, the confidence index of the doctor between original image add MPR image group and original image group had significant difference (5.00 vs. 4.24, 4.76 vs. 4.29, 4.29 vs. 3.71), and the confidence index of the doctor of original image add MPR image group exceeded that of original image group (Plt;0.05). Conclusions MDCT plays a valuable role in diagnosis and location of intussusception, finding the reason caused intussusception and evaluation the hemodynamic impairment of being involved in bowel wall. Compared to simple axial image, axial image combine 3-dimensional reconstructed image can increase the diagnostic confidence of the doctor.
Etiological and prognostic studies always directly reported effect size with its 95% confidence interval, hence, data transformation was needed when performing meta-analysis based on these studies. Using the data of risk ratio, hazard ratio, odds ratio and 95% confidence interval as an example, this paper introduces the process of using RevMan 5.3 software to convert data and perform meta-analysis.
Most statistical data in observational studies is expressed as the effect value and its 95% confidence interval (95% CI), which do not correspond to the data format used for traditional meta-analyses, so special data conversion is to be needed when Review Manager software is applied to do a meta-analysis for this type of data, which will make the operation complicated and cumbersome. In addition, Stata software is such a powerful statistical software that can be used directly to conduct a meta-analysis with the effect value and its 95% CI. Therefore, it is an indispensable statistical tool for meta-analysis in observational studies. And this study will give a brief introduction how to use Stata software to conduct a meta-analysis with effect value and its 95% CI based on the published meta-analysis data.