title: Causation, bias and confounding: a hitchhiker's guide to the epidemiological galaxy. Part 1. Principles of causality in epidemiological research: time order, specification of the study base and specificity.
authors.affiliation: Department of Epidemiology, University of Cape Town, Cape Town, South Africa. samshap@mweb.co.za
authors.forename: Samuel
authors.initials: S
authors.lastname: Shapiro
mesh_terms: D015982:Bias; D016022:Case-Control Studies; D015984:Causality; D015986:Confounding Factors, Epidemiologic; D004812:Epidemiologic Methods; D006801:Humans