title: Primum non nocere and the quality of evidence: rethinking the ethics of screening.
abstract: BACKGROUND
  Screening is different from investigation, and these differences have important implications in the assessment of screening programs.
  
  
  METHODS
  I review the differences between screening and investigation and the implications of these differences derived from a consideration of the four ethical principles of beneficence, nonmaleficence, autonomy, and distributive justice.
  
  
  RESULTS
  Because most of the harms of screening fall on the healthy and because screening is initiated by physicians, nonmaleficence takes ethical precedence over beneficence. Issues related to cost and consent are also approached differently in screening compared with investigation, and both take on greater ethical importance. I contend further that these ethical implications require that screening programs be backed up by better evidence than is the usual case for investigative medicine. I suggest an outline for the appropriate assessment of screening programs and for the ethical responsibilities of those involved in screening.
  
  
  CONCLUSIONS
  Many current medical screening practices are not concordant with our ethical principles and should be reassessed.
authors.affiliation: Department of Family & Community Medicine, Southern Illinois University School of Medicine, Springfield 62702-5238, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Ewart
mesh_terms: D004992:Ethics, Medical; D019317:Evidence-Based Medicine / Q000331:legislation & jurisprudence / Q000592:standards*; D006801:Humans; D008403:Mass Screening / Q000331:legislation & jurisprudence; D017009:Professional Autonomy; D011634:Public Health / Q000331:legislation & jurisprudence; D018570:Risk Assessment; D012935:Social Justice / Q000331:legislation & jurisprudence