Journal
STATISTICAL METHODS IN MEDICAL RESEARCH
Volume 26, Issue 3, Pages 1053-1077Publisher
SAGE PUBLICATIONS LTD
DOI: 10.1177/0962280214567141
Keywords
Survival analysis; Cox proportional hazards model; discrimination; predictive accuracy; Monte Carlo simulations; predictive models; risk factors; model performance
Categories
Funding
- Institute for Clinical Evaluative Sciences (ICES) - Ontario Ministry of Health and Long-Term Care (MOHLTC)
- Canadian Institutes of Health Research (CIHR) [MOP 86508]
- Heart and Stroke Foundation
- Center for Translational Molecular Medicine (PCMM project)
- U-award [AA022802]
- CIHR Team Grant in Cardiovascular Outcomes Research
Ask authors/readers for more resources
Predicting outcomes that occur over time is important in clinical, population health, and health services research. We compared changes in different measures of performance when a novel risk factor or marker was added to an existing Cox proportional hazards regression model. We performed Monte Carlo simulations for common measures of performance: concordance indices (c, including various extensions to survival outcomes), Royston's D index, R-2-type measures, and Chambless' adaptation of the integrated discrimination improvement to survival outcomes. We found that the increase in performance due to the inclusion of a risk factor tended to decrease as the performance of the reference model increased. Moreover, the increase in performance increased as the hazard ratio or the prevalence of a binary risk factor increased. Finally, for the concordance indices and R-2-type measures, the absolute increase in predictive accuracy due to the inclusion of a risk factor was greater when the observed event rate was higher (low censoring). Amongst the different concordance indices, Chambless and Diao's c-statistic exhibited the greatest increase in predictive accuracy when a novel risk factor was added to an existing model. Amongst the different R-2-type measures, O'Quigley etal.'s modification of Nagelkerke's R-2 index and Kent and O'Quigley's w,a2 displayed the greatest sensitivity to the addition of a novel risk factor or marker. These methods were then applied to a cohort of 8635 patients hospitalized with heart failure to examine the added benefit of a point-based scoring system for predicting mortality after initial adjustment with patient age alone.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available