Comparison of Cox Model Methods in A Low-dimensional Setting with Few Events
- Author:
Ojeda M FRANCISCO
1
;
Muller CHRISTIAN
;
Bornigen DANIELA
;
Tregouet DAVID-ALEXANDRE
;
Schillert ARNE
;
Heinig MATTHIAS
;
Zeller TANJA
;
Schnabel B RENATE
Author Information
1. Department of General and Interventional Cardiology
- Keywords:
Proportional hazards regres-sion;
Penalized regression;
Events per variable;
Coronary artery disease
- From:
Genomics, Proteomics & Bioinformatics
2016;14(4):235-243
- CountryChina
- Language:Chinese
-
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 tech-niques, (ii) backward elimination (BE), (iii) ridge regression, (iv) least absolute shrinkage and selec-tion 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 accu-racy, calibration, and discrimination of these approaches. Candidate predictors for incident cardio-vascular 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 compara-ble 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.
