caa a22 4500 605476195 CHVBK 20210128100355.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s10985-015-9335-y doi (NATIONALLICENCE)springer-10.1007/s10985-015-9335-y Does Cox analysis of a randomized survival study yield a causal treatment effect? [Elektronische Daten] [Odd Aalen, Richard Cook, Kjetil Røysland] Statistical methods for survival analysis play a central role in the assessment of treatment effects in randomized clinical trials in cardiovascular disease, cancer, and many other fields. The most common approach to analysis involves fitting a Cox regression model including a treatment indicator, and basing inference on the large sample properties of the regression coefficient estimator. Despite the fact that treatment assignment is randomized, the hazard ratio is not a quantity which admits a causal interpretation in the case of unmodelled heterogeneity. This problem arises because the risk sets beyond the first event time are comprised of the subset of individuals who have not previously failed. The balance in the distribution of potential confounders between treatment arms is lost by this implicit conditioning, whether or not censoring is present. Thus while the Cox model may be used as a basis for valid tests of the null hypotheses of no treatment effect if robust variance estimates are used, modeling frameworks more compatible with causal reasoning may be preferrable in general for estimation. Springer Science+Business Media New York, 2015 Causation nationallicence Collapsible model nationallicence Confounding nationallicence Hazard function nationallicence Survival data nationallicence Aalen Odd Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway aut Cook Richard Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Canada aut Røysland Kjetil Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway aut Lifetime Data Analysis Springer US; http://www.springer-ny.com 21/4(2015-10-01), 579-593 1380-7870 21:4<579 2015 21 10985 https://doi.org/10.1007/s10985-015-9335-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10985-015-9335-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Aalen Odd Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway aut NATIONALLICENCE 700 1- Cook Richard Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Canada aut NATIONALLICENCE 700 1- Røysland Kjetil Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway aut NATIONALLICENCE 773 0- Lifetime Data Analysis Springer US; http://www.springer-ny.com 21/4(2015-10-01), 579-593 1380-7870 21:4<579 2015 21 10985