Primum non nocere and the quality of evidence: rethinking the ethics of screening

Screening is different from investigation, and these differences have important implications in the assessment of screening programs.

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.

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.

Many current medical screening practices are not concordant with our ethical principles and should be reassessed.