Issues underlying the evaluation of screening programmes.

Screening programmes have the potential to prevent premature death and disability and to improve quality of life, but they also have the potential for harm. Identifying worthwhile screening programmes, developing the correct strategies, and implementing them effectively is no easy task. A much more critical approach to screening is now being adopted and efforts are being made to ensure that new programmes of proven benefit and which are acceptable to the public, are effectively and equitably implemented in the community. We hope that this issue will stimulate further discussion and debate.