A Multistage Testing Approach to Group-Score Assessments

2016 ◽  
pp. 409-428
Reproduction ◽  
2000 ◽  
pp. 225-229 ◽  
Author(s):  
A Gul ◽  
C Kotan ◽  
I Dilek ◽  
T Gul ◽  
A Tas ◽  
...  

The aim of this study was to determine whether autologous erythrocyte suspension can be used as a dye for evaluation of tubal patency and whether it has any advantages over methylene blue or indigo carmine solutions. Reproductively healthy female nulliparous Wistar Albino rats (n = 30), aged 6 months, mass 165-195 g, were assigned randomly to three groups. Rats received a 1 ml i.p. injection of 5% (w/v) methylene blue solution (methylene blue group: n = 10), 5% (w/v) indigo carmine solution (indigo carmine group: n = 10) or 5% (v/v) fresh autologous erythrocyte suspension (autologous erythrocyte group: n = 10). At 4 weeks after injection, a small sterile opening was made in the peritoneal cavity of each rat. The cavity was rinsed once with TCM-199 to collect macrophages. The rinsed peritoneal contents were cultured overnight to evaluate macrophage activation. The peritoneal opening was expanded for evaluation of adhesion formation. Only one rat from the autologous erythrocyte group had intra-peritoneal adhesions (score 2), whereas all rats in the methylene blue group (score 1: n = 1; score 2: n = 4; score 3: n = 4; and score 4: n = 1) and seven rats in the indigo carmine group (score 1: n = 1; score 2: n = 2; score 3: n = 3; and score 4: n = 1) had intra-abdominal adhesions. Macrophage activity was observed in the cultured peritoneal contents collected from the methylene blue and indigo carmine groups but not from the autologous erythrocyte group. Adhesion formation could be due to macrophage activation caused by methylene blue and indigo carmine solutions. These results indicate that tubal patency can be observed by laparoscopy using autologous erythrocyte suspension. The results of this study are believed to be the first to indicate that a patient's own erythrocyte suspension could be used during observation of tubal patency by laparoscopy. However, further studies are required.


2020 ◽  
pp. 1-17
Author(s):  
Erin Hartman

Abstract Regression discontinuity (RD) designs are increasingly common in political science. They have many advantages, including a known and observable treatment assignment mechanism. The literature has emphasized the need for “falsification tests” and ways to assess the validity of the design. When implementing RD designs, researchers typically rely on two falsification tests, based on empirically testable implications of the identifying assumptions, to argue the design is credible. These tests, one for continuity in the regression function for a pretreatment covariate, and one for continuity in the density of the forcing variable, use a null of no difference in the parameter of interest at the discontinuity. Common practice can, incorrectly, conflate a failure to reject evidence of a flawed design with evidence that the design is credible. The well-known equivalence testing approach addresses these problems, but how to implement equivalence tests in the RD framework is not straightforward. This paper develops two equivalence tests tailored for RD designs that allow researchers to provide statistical evidence that the design is credible. Simulation studies show the superior performance of equivalence-based tests over tests-of-difference, as used in current practice. The tests are applied to the close elections RD data presented in Eggers et al. (2015b).


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