SCREENING FOR DISEASE
SCREENING: DEFINITION• The PRESUMPTIVE identification of UNRECOGNIZED disease or defect by the application of tests, exams or other procedures which can be applied RAPIDLY to sort out apparently well persons who PROBABLY have a disease from those who PROBABLY do not”*
Principles for Screening Programs
• Condition should be an important health problem• There should be a recognizable early or latent stage
• There should be an accepted treatment for persons with condition
• The screening test is valid, reliable, with acceptable yield
• The test should be acceptable to the population to be screened
• The cost of screening and case finding should be economically balanced in relation to medical care as a whole
Validity of Screening Test (Accuracy)
- Sensitivity: Is the test detecting true cases of disease? (Ideal is 100%: 100% of cases are detected)-Specificity: Is the test excluding those without disease? (Ideal is 100%: 100% of non-cases are negative)