Results 31 to 40 of about 359,465 (284)
Estimation of treatment effects in weighted log-rank tests
Contemporary Clinical Trials Communications, 2017 Non-proportional hazards have been observed in clinical trials. The log-rank test loses power and the standard Cox model generally produces biased estimates under such conditions.
Ray S. Lin, Larry F. León
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An exact corrected log-likelihood function for Cox's proportional hazards model under measurement error and some extensions [PDF]
, 2002 This paper studies Cox`s proportional hazards model under covariate measurement error. Nakamura`s (1990) methodology of corrected log-likelihood will be applied to the so called Breslow likelihood, which is, in the absence of measurement error ...
Augustin, Thomas
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Non‐proportional hazards in immuno‐oncology: Is an old perspective needed? [PDF]
Pharmaceutical Statistics, 2020 AbstractA fundamental concept in two‐arm non‐parametric survival analysis is the comparison of observed versus expected numbers of events on one of the treatment arms (the choice of which arm is arbitrary), where the expectation is taken assuming that the true survival curves in the two arms are identical.
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Frontiers in Endocrinology, 2023 BackgroundThe use of surgery is controversial in patients with stage T3 or T4 triple-negative breast cancer (TNBC). We aimed to explore the effect of surgical treatment on overall survival (OS) of these patients.MethodsA total of 2,041 patients were ...
Jie Hu +12 more
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Gene selection in microarray survival studies under possibly non-proportional hazards [PDF]
Bioinformatics, 2010 AbstractMotivation: Univariate Cox regression (COX) is often used to select genes possibly linked to survival. With non-proportional hazards (NPH), COX could lead to under- or over-estimation of effects.The effect size measure c=P(T1<T0), i.e.
Daniela, Dunkler +2 more
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Contemporary Clinical Trials Communications, 2015 The semi-parametric proportional hazards model is widely adopted in randomized clinical trials with time-to-event outcomes, and the log-rank test is frequently used to detect a potential treatment effect.
Pei He, Zheng Su
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Cardiovascular Diabetology, 2023 Background The atherogenic index of plasma (AIP) can reflect the burden of atherosclerosis. Hyperglycemia is one of the leading causes of atherosclerosis. However, the relationship between AIP and prediabetes is rarely studied.
Xiaodan Zheng +4 more
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Restricted mean survival time: an alternative to the hazard ratio for the design and analysis of randomized trials with a time-to-event outcome [PDF]
, 2013 BACKGROUND: Designs and analyses of clinical trials with a time-to-event outcome almost invariably rely on the hazard ratio to estimate the treatment effect and implicitly, therefore, on the proportional hazards assumption.
Mahesh KB Parmar, Patrick Royston
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Dynamic Random Effects Models for Times between Repeated Events [PDF]
, 2001 We consider recurrent event data when the duration or gap times between successive event occurrences are of intrinsic interest. Subject heterogeneity not attributed to observed covariates is usually handled by random effects which result in an ...
Fong, DYT, Lam, KF, Lawless, JF, Lee, YW
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Mathematical methods and models for radiation carcinogenesis studies [PDF]
, 1986 Research on radiation carcinogenesis requires a twofold approach. Studies of primary molecular lesions and subsequent cytogenetic changes are essential, but they cannot at present provide numerical estimates of the risk of small doses of ionizing ...
A.M. Kellerer +25 more
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