August 30, 2023 In this article that appeared in a special issue in the Biometrical Journal, Chen et al describe how restricted mean survival time (RMST), an alternative representation of survival time, can be adapted to have clustering. They were motivated by multicenter randomized trials or cluster randomized trials. …

Issues in COVID-19 research and statistical analyses (08.16.23) The authors developed a proportional incidence model to estimate vaccine effectiveness (VE) but at the population level. Understanding VE during the COVID-19 pandemic was very important. Since obtaining individual level data linkages, the authors used aggregated counts from publicly available registries of…

August 2, 2023 In this article published in June online, Lancker et al describe a way for valid inference of hazard ratios from a Cox regression after variable selection. The problem has been that it is unknown which amount of covariates to use to control for confounding and informative censoring…

July 19, 2023 The authors, Ning et al, have proposed what they refer to as a “broad class” of “so called” Cox-Aalen transformation models which have elements of both multiplicative and additive covariate effects on the baseline hazard function contained within the transformation. Originally, the Cox proporiotnal hazards regression model…

July 5, 2023 The restricted mean survival time (RMST) is a concept that has been invented in survival analysis as an alternative to the hazards ratio, which can be difficult to interpret and also, as derived from Cox model, can have difficulty fitting into the proportional hazards assumption. The RMST…

June 21, 2023 Quantile regression has been around for awhile but has not been used so extensivly in survival analysis, namely for comparisons at the population level. …

June 7, 2023 The authors reviewed methods for complex survival data in terms of frailty models, like the recent advances and R packages. They explored areas of clustered outcomes, competing risks, illness-death model. They did admit their review did not cover two popular methods for clustered data: marginal Cox or…

May 24, 2023 The authors developed a semiparametric maximum likelihood estimation procedure via a kernel smoothed-aided expectation-maximization algorithm. The variances for this were estimated through weighted bootstrap. The authors focused on this for the illness-death model with accelerated failure time models (AFT) for each transition to different states of state0…

May 10, 2023 The authors Sun et al present a semi-competing risks framework using a flexible two-parameter copula-based semiparametric transformation model with interval censoring and left truncation. The semi-parametric transformation model allow both proportional hazards and proportional odds in both margins. …