V základním vyjádření je statistická síla pravděpodobnost dosažení statistické významnosti. Tři faktory (effect-size – velikost zamýšleného efektu), α, n), spolu se statistickou silou, tvoří uzavřený systém – pokud jsou všechny tři ustaveny, je tím zároveň i kompletně určen čtvrtý. Cílem silové analýzy je najít vhodnou rovnováhu mezi těmito faktory při zohlednění podstatných cílů studie. Ilustrujeme význam role velikosti zamýšleného efektu, α, a n na síle jednostranného F-testu, abychom poskytli celkový obrázek o pojetí konceptu statistické síly (testu)., In very basic terms, statistical power is the likelihood of achieving statistical significance. Three factors (effect-size, α, n), together with power, form a closed system – once any three are established, the fourth is completely determined. The goal of a power analysis is to find an appropriate balance among these factors by taking into account the substantive goals of a study. We exemplify the role of effect-size, α, and n on the power of a 1-sided F-test and give a general illustration of the power concept., Stepman H., Stöckl D., and Literatura 8
Motivation. Our previous study showed differences in the atherosclerosis phenotype between Lithuanian and Swedish men that could be influenced by complementary factors, namely oxidation processes and/or oxidative stress. The goal of this study was to evaluate the mainstream biological pathways inducing and maintaining the atherosclerotic process by analyzing genetic biomarkers particularly in inflammatory and metabolic pathways where the main focus is laid on the oxidation process. Methods. There were 32 families recruited for the study and clinical as well as biochemical analyses were performed. For genetic analysis 150 SNPs in 89 genes were selected in order to construct a microarray based on Arrayed Primer Extension (APEX) genotyping technology. Genotyping was carried out in 28 families and transmission disequilibrium test (TDT), siblingTDT (STDT), and combined analysis were performed. Results. Clinical and biochemical analysis revealed that probands with premature CAD were more likely to have diabetes mellitus, arterial hypertension, dyslipidemia and were male with high body mass index. Genetic analysis showed six SNPs statistically significantly associated with the atherosclerosis phenotype in the candidate genes ITGA2, IL1B, ALOX5A, OR13G1, MMP9 and NFKB1. These genes belong to different biological pathways: trombocyte adhesion and vessel damage, inflammation response, cholesterol and lypoxygenase metabolic pathway and nutrition. Conclusions. Generalized clinical, biochemical, bioinformatical and candidate genes association results support our hypothesis and indicate that the oxidation process may be of key importance in the formation of atherosclerosis., Ingrida Pepalyte, Zita Aušrele Kučinskiene, Kristina Grigalioniene, Žaneta Petrulioniene, Vilma Dženkevičiute, Loreta Bagdonaite, Vaidutis Kučinskas, and Literatura