ABSTRACT
Medical survival censored data of nearly 900 patients are evaluated to compare two basic surgical techniques. Data comes from patients who underwent colectomy in the University Hospital in Ostrava. Two basic surgery techniques are used for the colectomy: either classical (open) or laparoscopic operation. Basic question which arises at the colectomy operation is which type of operation to choose to guarantee longer overall survival time. Two methodological approaches have been used to answer this question. First is the semiparametric Cox proportional hazards model, what is the survival time model that has a fully parametric regression structure but leaves their dependence on time unspecified. The second approach is the parametric Weibull proportional hazards regression model, used because of the fact that the hazard function of human life is often described as being “bathtub shaped”.
