Facultade de Fisioterapia

Comparison of two discrimination indexes in the categorisation of continuous predictors in time-to-event studies

Barrio, I.; Rodríguez Álvarez, María Xosé; Meira Machado, L.; Esteban, C.; Arostegui, I.
Abstract:
The Cox proportionalhazards model is the most widely used survival predictionmodel for analysing time-to-event data. To measure the discrimination ability of a survival model the concordance probability index is widely used. In this work we studied and compared the performance of two different estimators of the concordance probability when a continuous predictor variable is categorised in a Cox proportional hazards regression model. In particular, we compared the c-index and the concordance probability estimator. We evaluated the empirical performance of both estimators through simulations. To categorise the predictor variable we propose a methodology which considers the maximal discrimination attained for the categorical variable. We applied this methodology to a cohort of patients with chronic obstructive pulmonary disease, in particular, we categorised the predictor variable forced expiratory volume in one second in percentage.
Year:
2017
Type of Publication:
Article
Journal:
SORT
Volume:
41
Number:
1
Pages:
73-92
Month:
June
DOI:
https://doi.org/10.2436/20.8080.02.51
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