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Emmanuel O. Ogundimu

Researcher at University of Oxford

Publications -  19
Citations -  932

Emmanuel O. Ogundimu is an academic researcher from University of Oxford. The author has contributed to research in topics: Sample size determination & Selection (genetic algorithm). The author has an hindex of 9, co-authored 18 publications receiving 676 citations. Previous affiliations of Emmanuel O. Ogundimu include Northumbria University & Durham University.

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Sample size considerations for the external validation of a multivariable prognostic model: a resampling study.

TL;DR: This study suggests that externally validating a prognostic model requires a minimum of 100 events and ideally 200 (or more) events, and provides guidance on sample size for investigators designing an external validation study.
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Adequate sample size for developing prediction models is not simply related to events per variable.

TL;DR: The results indicated that an EPV rule of thumb should be data driven and that EPV ≥ 20 generally eliminates bias in regression coefficients when many low-prevalence predictors are included in a Cox model.
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Quantifying the impact of different approaches for handling continuous predictors on the performance of a prognostic model.

TL;DR: Three broad approaches for handling continuous predictors are examined, including various methods of categorising predictors, modelling a linear relationship between the predictor and outcome and modelling a nonlinear relationship using fractional polynomials or restricted cubic splines.
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A Sample Selection Model with Skew-normal Distribution

TL;DR: In this article, a generalized Heckman selection model was proposed to capture spurious skewness in bounded scores, and in modelling data where logarithm transformation could not mitigate the effect of inherent skewness in the outcome variable.