Multistate, Multiepisode, and Interval‐Censored Models in Survival Analysis

2017 ◽  
Vol 47 (8) ◽  
pp. 1066-1074 ◽  
Author(s):  
L.C. Melo ◽  
R. Schneider ◽  
R. Manso ◽  
J.-P. Saucier ◽  
M. Fortin

Survival analysis methods make better use of temporal information, accommodate multiple levels of explanatory variables, and are meant to deal with interval-censored data. In a context of harvest modeling, this approach could improve some known limitations. In this study, we used data from a network of permanent plots in the province of Quebec, Canada, as a real-world case study. We tested the potential of survival analysis to predict plot-level harvest probabilities from plot- and regional-level variables. The approach also included random effects to account for spatial correlations. The results showed the potential of survival analysis to provide annual predictions of harvest occurrence. Both regional and time-varying variables, as well as spatial patterns, had important effects on the probability of a plot to be harvested. Respectively, reductions in the annual allowable cut volumes led to a decrease in the harvest probabilities. Greater harvest probabilities were associated with the broadleaved dynamics class and higher values of basal area. In contrast, they were decreased by stem density and slope classes. The spatial random effect resulted in an improvement of the model fit. Our plot-level model improved some limitations reported in previous studies by taking the effect of a time-varying regional variable into account.


2021 ◽  
pp. 1-6
Author(s):  
Federico E. Vaca ◽  
Kaigang Li ◽  
Xiang Gao ◽  
Katie Zagnoli ◽  
Haonan Wang ◽  
...  

2015 ◽  
Vol 35 (8) ◽  
pp. 1390-1400 ◽  
Author(s):  
Hae-Young Kim ◽  
John M. Williamson ◽  
Hung-Mo Lin

2020 ◽  
Vol 25 (30) ◽  
Author(s):  
Sarah Omar ◽  
Christoph Bartz ◽  
Sabine Becker ◽  
Silke Basenach ◽  
Sandra Pfeifer ◽  
...  

We analysed consecutive RT-qPCR results of 537 symptomatic coronavirus disease (COVID-19) patients in home quarantine. Respectively 2, 3, and 4 weeks after symptom onset, 50%, 25% and 10% of patients had detectable RNA from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In patients with mild COVID-19, RNA detection is likely to outlast currently known periods of infectiousness by far and fixed time periods seem more appropriate in determining the length of home isolation than laboratory-based approaches.


2015 ◽  
Author(s):  
◽  
Tyler Cook

Survival analysis is a popular area of statistics dealing with time-to-event data. A special characteristic of survival data is the presence of censoring. Censoring occurs when the survival time is only partially known. In medical studies, censoring can be caused by patients dropping out of the study before their disease event occurs. This dissertation focuses on the analysis of interval-censored data, where the failure time is only known to belong to some interval of observation times. One problem researchers face when analyzing survival data is how to handle the censoring distribution. This is an important consideration because sometimes a patient's survival time is related to the time they drop out of the study. It is often assumed that these two times are unrelated, so special methods need to be developed when they are dependent. Part of this dissertation investigates the effectiveness of methods developed for interval-censored data with dependent censoring when the censoring is actually independent. The results of these simulation studies can provide guidelines for deciding between models when facing a practical problem where one is unsure about the dependence of the censoring distribution. Another important problem seen in survival analysis is variable selection. For example, doctors might want to identify a set of diagnostic tests or measurements that can predict patient survival. We propose an imputation approach for variable selection of interval-censored data that utilizes penalized likelihood procedures. This work is significant because researchers currently do not have many tools to select important variables related to the survival time for interval-censored data.


Author(s):  
Kris Bogaerts ◽  
Arnošt Komárek ◽  
Emmanuel Lesaffre

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