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Statistical survival analysis of male larynx‐cancer patients ‐ a case study
Author(s) -
Kardaun O.
Publication year - 1983
Publication title -
statistica neerlandica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 39
eISSN - 1467-9574
pISSN - 0039-0402
DOI - 10.1111/j.1467-9574.1983.tb00806.x
Subject(s) - covariate , proportional hazards model , survival function , nonparametric statistics , statistics , survival analysis , relative survival , larynx , medicine , regression analysis , estimation , mathematics , population , observational study , regression , nonparametric regression , cancer , hazard , surgery , cancer registry , engineering , chemistry , systems engineering , environmental health , organic chemistry
Abstract This paper deals with a concrete case: Of 90 male larynx‐cancer patients, diagnosed and treated in the period 1970–1978, either the survival time or, if the patient was still alive at the end of the study, an appropriate lower bound on it was recorded. One factor (stage of the cancer) and one covariate (age of the patient) were a priori selected as important variables possibly influencing the survival function. After an elementary analysis of the 3 and 5 year survival fractions in section 2, a nonparametric estimation of the survival functions ignoring the effect of age is presented in section 3. In the last section COX'S (1972) proportional hazards model is used for a one dimensional regression on age which leads to the estimation of S i (t z ), the survival function of patients with stage i and age z . This allows for a graphical comparison with the normal population. Finally some checks on the proportional hazard assumption are performed. The emphasis in this paper is on adequately applying and adapting (mostly existing) techniques, including the use of some generally available computer programs, to a practical case. Care has been given to model assumptions and theoretical foundations of the relevant methods.