A novel sample size formula for the weighted log-rank test under the proportional hazards cure model
نویسندگان
چکیده
منابع مشابه
Sample-size formula for the proportional-hazards regression model.
A formula is derived for determining the number of observations necessary to test the equality of two survival distributions when concomitant information is incorporated. This formula should be useful in designing clinical trials with a heterogeneous patient population. Schoenfeld (1981, Biometrika 68, 316-319) derived the asymptotic power of a class of statistics used to test the equality of t...
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An advantage of the supremum log-rank over the standard log-rank statistic is an increased sensitivity to a wider variety of stochastic ordering alternatives. In this article, we develop a formula for sample size computation for studies utilizing the supremum log-rank statistic. The idea is to base power on the proportional hazards alternative, so that the supremum log rank will have the same p...
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This power function can be used to • compute the power β with which the hypothesis test rejects a specific alternative ω1 > ω0 when the sample size is at some given value of n; • compute the sample size for which a hypothesis test would have prescribed power β to detect a specific “design” alternative ω1 > ω0; or • compute the alternative ω1 > ω0 which is rejected with prescribed power β when p...
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The Cox proportional hazards (PH) model with time-dependent covariates (referred to as the extended PH model) has been widely used in medical and health related studies to investigate the effects of time-varying risk factors on survival. Theories and practices regarding model estimation and fitting have been well developed for the extended PH model. However, little has been done regarding sampl...
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The proportional hazards curemodel generalizes Cox’s proportional hazardsmodel which allows that a proportion of study subjects may never experience the event of interest. Here nonparametricmaximum likelihood approach is proposed to estimating the cumulative hazard and the regression parameters. The asymptotic properties of the resulting estimators are established using the modern empirical pro...
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ژورنال
عنوان ژورنال: Pharmaceutical Statistics
سال: 2016
ISSN: 1539-1604
DOI: 10.1002/pst.1790