The effect of private attitudes on public policy. Prenatal screening for neural tube defects as a prototype.

The quantitative use of patients' attitudes in medicine has thus far been limited to decisions involving either treatment alternatives or the use or nonuse of a particular diagnostic test. Preference theory has not been applied either to the use of screening tests or to the development of large-scale health-related public policy decisions. In this paper we have, in a prototypical fashion, analyzed the effect patient attitudes have on a public policy decision faced by many countries today--whether or not to institute a screening program for neural tube defects. We have assessed the attitudes of 338 prospective parents toward many of the sequelae expected from the introduction, or lack thereof, of the alpha-fetoprotein screening program--induced abortion from amniocentesis, elective abortion, and the birth of a defective child. Using these data and information collected by the United Kingdom study on alpha-fetoprotein, we have estimated the proportion of patients coming to genetic counseling who would benefit from the availability of a screening program for neural tube defects.