A Longitudinal Study of the Bladder Cancer Applying a State-Space Model with Non-Exponential Staying Time in States
Metadatos
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Mdpi
Materia
Bladder cancer Matrix-analytic methods Phase-type distributions State-space models Survival
Date
2021-02-11Referencia bibliográfica
Montoro-Cazorla, D.; Pérez-Ocón, R.; Pereira das Neves-Yedig, A. A Longitudinal Study of the Bladder Cancer Applying a State-Space Model with Non-Exponential Staying Time in States. Mathematics 2021, 9, 363. [https://doi.org/10.3390/math9040363]
Résumé
A longitudinal study for 847 bladder cancer patients for a period of fifteen years is
presented. After the first surgery, the patients undergo successive ones (recurrences). A statemodel
is selected for analyzing the evolution of the cancer, based on the distribution of the times
between recurrences. These times do not follow exponential distributions, and are approximated by
phase-type distributions. Under these conditions, a multidimensional Markov process governs the
evolution of the disease. The survival probability and mean times in the different states (levels) of
the disease are calculated empirically and also by applying the Markov model, the comparison of
the results indicate that the model is well-fitted to the data to an acceptable significance level of 0.05.
Two sub-cohorts are well-differenced: those reaching progression (the bladder is removed) and those
that do not. These two cases are separately studied and performance measures calculated, and the
comparison reveals details about the characteristics of the patients in these groups.