NON-PROPORTIONAL HAZARDS WITH APPLICATION TO KIDNEY TRANSPLANT DATA

a new type-ii fuzzy logic based controller for non-linear dynamical systems with application to 3-psp parallel robot

abstract type-ii fuzzy logic has shown its superiority over traditional fuzzy logic when dealing with uncertainty. type-ii fuzzy logic controllers are however newer and more promising approaches that have been recently applied to various fields due to their significant contribution especially when the noise (as an important instance of uncertainty) emerges. during the design of type- i fuz...

Survival analysis: coping with non proportional hazards in randomized trials

Almost all trials with a censored time-to-event outcome are designed, powered and analysed with a target hazard ratio for comparing experimental and control treatments in mind. Differences in survival experience between trial arms are tested with a logrank test and usually illustrated using a Kaplan-Meier plot. We describe this as an analysis in the probability domain. The focus is often on est...

Simulating Clustered Survival Data with Proportional Hazards Margins

Analysis of survival data from trials with non-proportional hazards: an empirical comparison of methods

Methods We analyse survival data reconstructed from two trials publications which reported extreme non-proportional hazards (with respective p-values as 9.19E-13 and 1.344E-24 in non-PH Grambsch-Thernau test). We use the Cox proportional hazards model, flexible parametric model and accelerated failure time model to estimate the time-independent hazard ratio, between-arm difference in restricted...

Two Level Proportional Hazards

We extend the proportional hazards model to a two level model with a random intercept term and random coeecients. The parameters in the multilevel model are estimated by a combination of EM and Newton-Raphson algorithms. Even for samples of 50 groups, this method produces estimators of the regression coeecient which are approximately unbiased and normally distributed. Two diierent methods, obse...