0000000000460677
AUTHOR
Amel Mahboubi
Empirical study of the dependence of the results of multivariable flexible survival analyses on model selection strategy
Flexible survival models, which avoid assumptions about hazards proportionality (PH) or linearity of continuous covariates effects, bring the issues of model selection to a new level of complexity. Each ‘candidate covariate’ requires inter-dependent decisions regarding (i) its inclusion in the model, and representation of its effects on the log hazard as (ii) either constant over time or time-dependent (TD) and, for continuous covariates, (iii) either loglinear or non-loglinear (NL). Moreover, ‘optimal’ decisions for one covariate depend on the decisions regarding others. Thus, some efficient model-building strategy is necessary. We carried out an empirical study of the impact of the model …
Multi-state relative survival modelling of colorectal cancer progression and mortality.
Abstract Accurate identification of factors associated with progression of colorectal cancer remains a challenge. In particular, it is unclear which statistical methods are most suitable to separate the effects of putative prognostic factors on cancer progression vs cancer-specific and other cause mortality. To address these challenges, we analyzed 10 year follow-up data for patients who underwent curative surgery for colorectal cancer in 1985–2000. Separate analyses were performed in two French cancer registries. Results of three multivariable models were compared: Cox model with recurrence as a time-dependent variable, and two multi-state models, which separated prognostic factor effects …
How do gastroenterologists follow patients with colorectal cancer after curative surgical resection? A three-year population-based study
Summary Objectives To assess the contribution of gastroenterologists (GEs) to the surveillance of colorectal cancer after curative surgery. Patients and methods This registry-based study included 407 patients residing in two French administrative areas diagnosed with newly diagnosed colorectal cancer in 1998 and free of disease six months after curative surgery. All surveillance examinations performed either in the three years after surgery or until death or recurrence were collected retrospectively. Results One hundred nine patients (27%) had a regular clinical check-up with a GE at least once a year. Factors independently associated with GE follow-up were young age (P=0.004), use of adjuv…