Exposició GRASS

Ponents: Klaus Langohr, Lupe Gómez i Montse Rué - Dimarts 19 de març 2013


De 10:00 a 12:00

10:00 - Klaus Langohr i Lupe Gómez

Títol: Quantile estimation of the rejection distribution of food products integrating assessor values and interval-censored consumer data.


Resum:
Fitting parametric survival models with interval-censored data is a common task in survival analysis and implemented in many statistical software packages. Here, we present a novel approach to fit such models if the values on the scale of interest are measured with error. Random effects ANOVA models are used to account for the measurement errors and the likelihood function of the parametric survival model is maximized with numerical methods using R. An illustration is provided with a real data set on the rejection of yogurt as a function of its acid taste.


11:00 - Montse Rué:
Títol: A brief introduction to risk models for prostate cancer incidence.


Resum:

Prostate specific antigen (PSA) is a biomarker for prostate cancer (PCa).

PSA is widely used to screen for PCa. On one hand, the results of the two biggest randomized studies assessing the effect of PCa screening are contradictory. On the other hand, PCa screening has a major side effect, the overdiagnosis of indolent PCa cases. We think that joint models of longitudinal PSA measures and time to incidence of PCa may be useful to obtain a better measure of the individual risk of PCa and to discriminate indolent from aggressive tumors. I will present the state of the art on PCa risk measurement and the objectives of our future joint work.