Screening Flashcards
What is screening?
The process of identifying healthy people who may have an increased chance of a disease or condition
What are some benefits of screening?
- Save lives or improve quality of life through early identification of a condition
- Reduce the chance of developing a serious condition or its complication
What is the Wilson and Jungner criteria in relation to the condition?
- Important public health problem
- Natural history understood
- Recognisable latent or early symptomatic phase
What is the Wilson and Jungner criteria relating to the test?
- Simple, safe, precise and validated
- Acceptable
- Distribution of test results known and cut-off defined
- Agreed policy on further diagnostic investigations
What is the Wilson and Jungner criteria relating to the treatment?
Effective and available
What is the Wilson and Jungner criteria in relation to the screening programme?
- Evidence from RCTs that screening is effective/accurate
- Clinically, socially and ethically acceptable
- Cost effective
- Quality assured
What is sensitivity?
How well the test picks up having the disease
What is the equation for sensitivity?
Number of people with the disease
What is specificty?
How well the test detects not having the disease
What is the equation for specificity?
Number of people without the disease
What is the difference between high sensitivity and high specificity?
Highly sensitive test:
- Picks up most of the disease
- Very few false negatives
Highly specific test:
- Correctly detects no disease
- Very few false positives
What is the positive predictive value?
How reliable the test result which shows the disease is present is
What is the equation for positive predictive value?
Number of people with a positive test result
What is the negative predictive value?
How reliable the test result showing disease is not present is
What is the equation for negative predictive value?
Number of people with a negative test result
