Results 321 to 330 of about 6,212,855 (344)

Derivation of hazard ratios

BMJ, 2011
Researchers investigated the extent to which referral from primary care for defined symptoms of hip pain varied by age, sex, and social deprivation in the United Kingdom. A cohort study design was used. Data for individual patients registered at 326 general practices between 2001 and 2007 were extracted from the health improvement network database in ...
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A comparison of two simple hazard ratio estimators based on the logrank test.

Statistics in Medicine, 1991
Two hazard ratio estimators based on the logrank test are investigated using a simulation study. The Pike estimator (ratio of relative death rates) was shown to be consistently less biased than the Peto (1-step) estimator.
Tosiya Sato, G. Berry
semanticscholar   +2 more sources

Hazards of Hazard Ratios — Deviations from Model Assumptions in Immunotherapy

New England Journal of Medicine, 2018
Look Beyond Hazard Ratios Many trials are based on the proportional-hazards assumption that an event is equally likely in different treatment groups over time and deviations are related to the intervention. Full Kaplan–Meier estimates from earlier trials may be more informative than summary statistics.
Brian M. Alexander, Jonathan D. Schoenfeld, Lorenzo Trippa   +2 more
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Nonparametric estimation of cause-specific cross hazard ratio with bivariate competing risks data

, 2008
We propose an alternative representation of the cause-specific cross hazard ratio for bivariate competing risks data. The representation leads to a simple plug-in estimator, unlike an existing ad hoc procedure.
Yu Cheng, J. Fine
semanticscholar   +1 more source

Time-Dependent Hazard Ratio: Modeling and Hypothesis Testing with Application in Lupus Nephritis

, 1996
We investigate the association between duration of untreated disease and survival in lupus nephritis, a rare rheumatologic disease. In this case, as in many other studies of survival, a priori considerations suggest that the effect of the predictor on ...
M. Abrahamowicz, T. Mackenzie, J. Esdaile   +2 more
semanticscholar   +1 more source

Estimating equations for hazard ratio parameters based on correlated failure time data

, 1995
SUMMARY Weighted partial likelihood estimating equations are proposed for the estimation of marginal hazard ratio parameters based on correlated failure time data.
Jianwen Cai, R. Prentice
semanticscholar   +1 more source

Nonparametric covariate adjustment in estimating hazard ratios

Pharmaceutical Statistics, 2015
In randomized clinical trials with time‐to‐event outcomes, the hazard ratio is commonly used to quantify the treatment effect relative to a control. The Cox regression model is commonly used to adjust for relevant covariates to obtain more accurate estimates of the hazard ratio between treatment groups.
Yanping Wang, Craig H. Mallinckrodt, Honghua Jiang, Pandurang M. Kulkarni   +3 more
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Hazard rate ratio and prospective epidemiological studies

Journal of Clinical Epidemiology, 2002
Analysis of prospective follow-up data usually includes a Cox regression model. When a hazard rate ratio, obtained as the exponential of an estimated regression coefficient from the Cox model, is greater than 1.0, it consistently exceeds relative risk, and is exceeded by the odds ratio.
D.T. Moore, M.J. Symons
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Hazard and Hazard Ratio

, 2008
The hazard function is a tool for describing the process of time to failure. Hazard functions arise in the context of survival analysis, also known as failure analysis, and provide a convenient way to visualize how the risk of failure changes with age or
R. Ray
semanticscholar   +1 more source

Two Useful Reformulations of the Hazard Ratio

The American Statistician, 2014
The hazard ratio is a standard summary for comparing survival curves yet hazard ratios are often difficult for scientists and clinicians to interpret. Insight into the interpretation of hazard ratios is obtained by relating hazard ratios to the maximum difference and an average difference between survival probabilities.
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