title: Bias in, bias out: a reply to Sheils, Young, and Rubin.
authors.forename: D U
authors.initials: DU
authors.lastname: Himmelstein
authors.forename: S
authors.initials: S
authors.lastname: Woolhandler
mesh_terms: D015982:Bias; D002170:Canada; D006801:Humans; D007348:Insurance, Health; D009313:National Health Programs / Q000191:economics* / Q000706:statistics & numerical data; D014481:United States