Some ethical and design challenges of screening programs and screening tests.

BACKGROUND: There are many examples of inadequate screening studies because of design faults and consent problems. ISSUES: Informed consent is the right of each person engaged in a clinical interaction, including service and research involvement in presymptomatic screening. Any screening approach must answer questions of efficacy, effectiveness, availability and efficiency. Accurate information, presented in clear language, must state a realistic assessment of the limitations, harms and benefits of the screening, including the consequences of false positive and false negative tests. There must be no coercive element in obtaining consent. Written and oral information should be presented. It is also important to recognize cultural differences between societies that emphasize individual autonomy and those in which autonomy derives from membership of a family, group or community, thus requiring different strategies to protect the vulnerable. Testing for genetic disorders presents additional challenges, partly due to the presence of relatively small numbers of affected individuals in the population, but also because of the complexity of counseling, confidentiality issues and the potential for social, insurance or employment discrimination.
CONCLUSIONS: It is becoming increasingly difficult to present the data for many screening procedures in ways that can be understood by possible participants, and at the same time deal clearly with the costs to society and the efficacy and efficiency of the tests.