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DOI: 10.1055/s-0038-1635470
Clinical Trial Size: Fixed versus Group-Sequential Designs
Fallzahl einer klinischen Studie: Fester oder gruppensequentieller Stichprobenumfang?Publication History
Publication Date:
19 February 2018 (online)
Summary
This paper deals with the estimation of the size of clinical trials for comparing two binomial proportions in both fixed and group-sequential designs. In the fixed size approach, it focuses on 1.) equal sample size design; 2.) unequal allocation designs that either maximize the test power subject to fixed total cost or minimize the total expenditure subject to prespecified power using the simplex procedure for function minimization. Emphasis is also placed on group-sequential designs, based upon closed stopping rules, multiple testing and range of clinical equivalence. The efficiency of different allocation designs is assessed by computing the power of the exact conditional Fisher-Irwin test. Designs were applied in planning a clinical trial in which the drug Pancuronium Bromide was compared with a standard treatment to reduce intraventricular haemorrhage in preterm infants.
Diese Arbeit befaßt sich mit der Schätzung des Umfangs bei klinischen Studien, wenn zwei binomiale Anteile sowohl bei festem als auch gruppensequentiellem Stichprobenumfang verglichen werden sollen. Im Falle des festen Stichprobenumfangs konzentriert sie sich auf 1.) gleiche Stichprobenumfänge, 2.) ungleiche Zuteilungsverfahren, die entweder bei festen Gesamtkosten die Macht des Tests maximieren oder bei vorgegebener Macht unter Benutzung eines Simplexverfahrens zur Bestimmung des Minimums einer Funktion die Gesamtkosten minimieren. Besonderer Wert wird auch auf gruppensequentielle Verfahren gelegt, die auf abgeschlossenen Stoppregeln, Mehrfachtests und dem Ausmaß klinischer Äquivalenz beruhen. Die Wirksamkeit verschiedener Zuteilungsverfahren wird beurteilt durch die Berechnung der Macht des exakten konditionalen Fisher-Irwin-Tests. Das Verfahren wurde zur Planung einer klinischen Studie angewandt, bei der das Arzneimittel Pancuronium-Bromid mit einer Standardtherapie zur Reduzierung intraventrikulärer Blutungen bei Frühgeburten verglichen wurde.
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