title: A competing risks approach to "biologic" interaction.
abstract: In epidemiology, the concepts of "biologic" and "statistical" interactions have been the subject of extensive debate. We present a new approach to biologic interaction based on Rothman's original (Am J Epidemiol, 104:587-592, 1976) discussion of sufficient causes. We do this in a probabilistic framework using competing risks and argue that sufficient cause interaction between two factors can be evaluated via the parameters in a particular statistical model, the additive hazard rate model. We present empirical conditions for presence of sufficient cause interaction and an example based on data from a liver cirrhosis trial illustrates the ideas.
authors.affiliation: Department of Biostatistics, University of Copenhagen, O. Farimagsgade 5, PB2099, 1014, Copenhagen K, Denmark, pka@biostat.ku.dk.
authors.forename: Per Kragh
authors.initials: PK
authors.lastname: Andersen
authors.forename: Anders
authors.initials: A
authors.lastname: Skrondal
mesh_terms: D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D015982:Bias; D001699:Biometry / Q000379:methods*; D015984:Causality; D015986:Confounding Factors, Epidemiologic; D003627:Data Interpretation, Statistical; D003718:Denmark; D015987:Effect Modifier, Epidemiologic; D006801:Humans; D008103:Liver Cirrhosis / Q000188:drug therapy / Q000401:mortality; D016012:Poisson Distribution; D011241:Prednisone / Q000627:therapeutic use; D016016:Proportional Hazards Models; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors
chemical_list: D000893:Anti-Inflammatory Agents; D011241:Prednisone