State of the Science Update: Preventive screening, false positives and “overdiagnosis.”

Background and issues: Preventive screening rests on a tightly held epidemiologic assumption that early disease detection saves lives and improves quality of life. A more complicated picture, however, arises from recent re-analyses of screening data. Providers are often reluctant to adopt screening recommendations based on new evidence; and patients demand screening tests, failing to understand absolute versus relative risk, and affirmed in their beliefs through health promotion and media messages. 

Description: Recent re-analyses of breast, prostate, and cervical cancer screening data were reviewed.  Current recommendations, screening practices, and provider and patient “uptake” of new recommendations were explored in the research literature.

Lessons-learned: Recent re-analyses of large-scale preventive screening program data indicate substantial “overdiagnosis” of disease. Mammography screening, for example, results in substantial false positive tests, leading to life-changing treatment for non-trivial numbers of women. Similarly, prostate surface antigen screening of asymptomatic men results in frequent treatment--with significant complications--of non-progressive disease. Widespread screening of “well” people may result in substantial harm for small numbers of lives saved as well as psychological and sociologic consequences of disease diagnoses. The cost of false positives evokes a re-examination of risk assessment and recommendations for preventive screening.