Power and Sample Size Determination in Survival Time Studies with Special Regard to the Censoring Mechanism^[*]

When calculating the power and sample size in survival time studies for the comparison of two treatments censoring has to be taken into account.

In most medical applications only vague information about the shape of the underlying distributions is available. Thus, a distribution-free procedure based on the McNemar test is proposed and compared with other methods.

Power- und Stichprobenkalkulationen in Uberlebenszeitstudien zum Vergleich zweier Behandlungen müssen den Einfluß, den der Zensierungsmechanismus ausübt, berücksichtigen.

Bei den meisten Anwendungen im Bereich der Medizin hat man oft nur eine sehr grobe Vorstellung über die Form der zugrundeliegenden Verteilungen. Deshalb wird ein Verfahren vorgeschlagen, das auf dem verteilungsfreien McNemar-Test beruht, und mit anderen Methoden verglichen.

Key-Words:

Survival Time Studies - Random Censorship - Power of 2-Sample Tests - Sample Size Determination - McNemar Test

Schlüssel-Wörter:

Uberlebenszeitstudien - Zufällige Zensierung - Power von Zwei-Stichprobentests - Stichprobenumfänge - McNemar-Test

^* This work has been supported by the Deutsche Forschungsgemeinschaft

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