Title
Comparison of Cox Model Methods in A Low-dimensional Setting with Few Events.
Abstract
Prognostic models based on survival data frequently make use of the Cox proportional hazards model. Developing reliable Cox models with few events relative to the number of predictors can be challenging, even in low-dimensional datasets, with a much larger number of observations than variables. In such a setting we examined the performance of methods used to estimate a Cox model, including (i) full model using all available predictors and estimated by standard techniques, (ii) backward elimination (BE), (iii) ridge regression, (iv) least absolute shrinkage and selection operator (lasso), and (v) elastic net. Based on a prospective cohort of patients with manifest coronary artery disease (CAD), we performed a simulation study to compare the predictive accuracy, calibration, and discrimination of these approaches. Candidate predictors for incident cardiovascular events we used included clinical variables, biomarkers, and a selection of genetic variants associated with CAD. The penalized methods, i.e., ridge, lasso, and elastic net, showed a comparable performance, in terms of predictive accuracy, calibration, and discrimination, and outperformed BE and the full model. Excessive shrinkage was observed in some cases for the penalized methods, mostly on the simulation scenarios having the lowest ratio of a number of events to the number of variables. We conclude that in similar settings, these three penalized methods can be used interchangeably. The full model and backward elimination are not recommended in rare event scenarios.
Year
DOI
Venue
2016
10.1016/j.gpb.2016.03.006
Genomics, Proteomics & Bioinformatics
Keywords
Field
DocType
Proportional hazards regression,Penalized regression,Events per variable,Coronary artery disease
CAD,Data mining,Selection operator,Proportional hazards model,Biology,Regression,Survival data,Elastic net regularization,Lasso (statistics),Prospective cohort study,Bioinformatics,Statistics
Journal
Volume
Issue
ISSN
14
4
1672-0229
Citations 
PageRank 
References 
0
0.34
0
Authors
8