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

The Cox proportional hazards model is the most widely used survival prediction model 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 est...

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Detalles Bibliográficos
Autores: Barrio Beraza, Irantzu|||0000-0003-0648-5769, Rodríguez-Álvarez, María Xosé|||0000-0002-1329-9238, Meira-Machado, Luis, Esteban, Cristóbal, Arostegui, Inmaculada|||0000-0002-6848-2240
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:176145
Acceso en línea:https://ddd.uab.cat/record/176145
https://dx.doi.org/urn:doi:10.2436/20.8080.02.51
Access Level:acceso abierto
Palabra clave:Categorisation
Prediction models
Cutpoint
Cox model
Descripción
Sumario:The Cox proportional hazards model is the most widely used survival prediction model 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.