This article introduces the definition and sample size estimation of three special tests (namely, non-inferiority test, equivalence test and superiority test) for qualitative data with the design of one factor with two levels having a binary response variable. Non-inferiority test refers to the research design of which the objective is to verify that the efficacy of the experimental drug is not clinically inferior to that of the positive control drug. Equivalence test refers to the research design of which the objective is to verify that the experimental drug and the control drug have clinically equivalent efficacy. Superiority test refers to the research design of which the objective is to verify that the efficacy of the experimental drug is clinically superior to that of the control drug. By specific examples, this article introduces formulas of sample size estimation for the three special tests, and their SAS realization in detail.

Sample size estimation is necessary for any experimental or survey research. An appropriate estimation of sample size based on known information and statistical knowledge is of great significance. This article introduces methods of sample size estimation of difference test for data with the design of one factor with two levels, including sample size estimation formulas and realization based on the formulas and the POWER procedure of SAS software for quantitative data and qualitative data with the design of one factor with two levels. In addition, this article presents examples for analysis, which will play a leading role for researchers to implement the repetition principle during the research design phase.

ABSTRACT: Estimation of sample size and testing power is an important component of research design. This article introduced methods for sample size and testing power estimation of difference test for quantitative and qualitative data with the single-group design, the paired design or the crossover design. To be specific, this article introduced formulas for sample size and testing power estimation of difference test for quantitative and qualitative data with the above three designs, the realization based on the formulas and the POWER procedure of SAS software and elaborated it with examples, which will benefit researchers for implementing the repetition principle.

This article introduces the general concepts and methods of sample size estimation and testing power analysis. It focuses on parametric methods of sample size estimation, including sample size estimation of estimating the population mean and the population probability. It also provides estimation formulas and introduces how to realize sample size estimation manually and by SAS software.

This article introduces definitions of three special tests, namely, non-inferiority test (to verify that the efficacy of the experimental drug is clinically not inferior to that of the positive control drug), equivalence test (to verify that the efficacy of the experimental drug is equivalent to that of the control drug) and superiority test (to verify that the efficacy of the experimental drug is superior to that of the control drug), and methods of sample size estimation under the three different conditions. By specific examples, the article introduces formulas of sample size estimation for the three special tests, and their SAS realization in detail.

The design of one factor with k levels (k≥3) refers to the research that only involves one experimental factor with k levels (k≥3), and there is no arrangement for other important non-experimental factors. This paper introduces the estimation of sample size and testing power for quantitative data and qualitative data having a binary response variable with the design of one factor with k levels (k≥3).

Objective To study the skills of laparoscopy for hight difficulty eholecystectomy.Method Forty-eight cases of hight difficulty laparoscopic cholecystectomy from July 2005 to July 2007 were analyzed retrospectively. Result In 48 cases, 5 cases were converted to open surgery, 2 cases suffered in-cision infection, all the patients recovered. Conclusion According to the operating status and experience of the performer, Calot triangle dissection and judge good opportunity to change open surgery are the key faetora to the successful operation for difficult and complex laparoscopie cholecystectomy, which is safe and feasible.

BACKGROUND:Now, domestic total knee arthroplasty surgeries mainly use medial parapatel ar approach, with the disadvantages of large trauma and slower recovery. The quadriceps sparing approach is more accorded with normal anatomy, which can keep the knee extension system intact. The clinical comparison between quadriceps sparing approach and medial parapatel ar approach is rare.
OBJECTIVE:To compare the early effect of total knee arthroplasty through quadriceps sparing approach and medial parapatel ar approach.
METHODS:From January 2009 to January 2010, 55 patients (70 knees) were randomly divided into quadriceps sparing approach group (n=26, 35 knees) and medial parapatel ar approach group (n=29, 35 knees). Patients in two groups received total knee arthroplasty through quadriceps sparing approach and medial parapatel ar
approach respectively. The incision length, operative time, postoperative drainage volume, additional amount of etoricoxib tablets, pain degree, straight leg raising time, start walking time, hospitalization time, range of motion of knee joint, Hospital for Special Surgery Knee Score, radiographic alignment of al components and complications were compared between two groups. Al the prostheses used in this study were the Sigma type prostheses
provided by the rotation platform of Johnson&Johnson Company.
RESULTS AND CONCLUSION:Al the patients were fol owed-up for 12-24 months without infections, deep vein thrombosis, neurovascular injury, prosthesis instability, prosthesis loosening or displacement. Position of al the
prostheses was normal in patients. The operative time in the quadriceps sparing approach group was longer than that in the medial parapatel ar approach group (P=0.00), while the incision length, postoperative drainage volume, additional
amount of etoricoxib tablets, visual analog scale, straight leg raising time, start walking time, hospitalization time, range of motion of knee joint at 3 days after replacement and Hospital for Special Surgery Knee Score in the quadriceps
sparing approach group were better than those in the medial parapatel ar approach group (P<0.05). There were no
significant differences in range of motion of knee joint at 3 days after replacement and Hospital for Special Surgery Knee Score between two groups. The early effect of total knee arthroplasty through quadriceps sparing approach is better than the medial parapatel ar approach, and there is no significant difference in prosthesis alignment between two methods.

The resident infection rate of schistosomiasis in Xinnong Village,Chuanxin Town,a national surveillance site of schistosomiasis.decreased to 0.14% in 2008.which suggested that the surveillance site reached the criteria for trammission control.

Objective To investigate the clinical efficiency of Huayu Xiaozhong Decoction (HXD) on preventing peri-operative deep venous thrombosis (DVT) in lower limbs following artificial total hip replacement. Methods Ninety cases following artificial total hip replacement were randomized into blank control group, Rivaroxaban group and HXD group, 30 cases in each group, and were treated with brown sugar water, Rivaroxaban, HXD respectively. Before operation, and one, 3 and 14 days after operation, we monitored the changes of bleeding volume, DVT incidence, hemoglobin, prothrombin time ( PT) , activated partial thromboplastin time ( APTT) , international normalized ratio (INR), and D-dimer (DD) in the three groups. Results (1) Fifteen cases had DVT, with a total incidence rate of 16.67%. Of the 15 cases, 10 were from blank control group, 2 from Rivaroxaban group, and 3 from HXD group. ( 2) The amount of bleeding volume of Rivaroxaban group was larger than that of the blank control group and HXD group (P<0.05), but the bleeding was mild. (3) One, 3 and 14 days after operation, PT and APTT were shortened in blank control group (P<0.01 compared with those before operation). PT, APTT and INR were prolonged, and coagulation function was improved in Rivaroxaban group and HXD group, the differences being significant as compared with the blank control group ( P<0.05). HXD group had better effect on improving INR than Rivaroxaban group ( P<0.05). ( 4) In the three groups, hemoglobin level began to decrease on postoperative day one, arrived to the bottom on postoperative day 3 (P<0.05), and rose up near to the normal level on postoperative day 14; HXD group had higher hemoglobin level than blank control group and Rivaroxaban group on postoperative day 3 and 14 ( P<0.05). The 3 groups had higher plasma DD level than the normal level before the operation, arrived to the highest level on postoperative day one and 3 ( P<0.05) , and fell down near to the normal level on postoperative day 14. The inter-group comparison results showed that Rivaroxaban group and HXD group had lower DD level than the blank control group on postoperative day 3 and 14 ( P<0.05). Conclusion HXD is effective on preventing DVT in the peri-operation period through reducing bleeding, increasing hemoglobin level and improving postoperative anemia. The efficiency and safety of HXD are similar to Rivaroxaban.