screening Flashcards
what is the phases of the natural history of disease
underlying
susceptible
subclinical
recovery/disability/death
what is primordial prevention
targets the population rather than individuals
focuses on social and environmental intervential
targets conditions that would lead to disease onset
what is primary prevention
targets susceptible populations of individual
prevent a disease from emerging and targets healthy individuals
reduces exposure to risk factors
what is secondary prevention
targets individuals with subclinical disease
early detection
screening programs
what is tertiary prevention
targets clinical and outcome stages of the disease
reduce disease severity and associated complications
what is quaternary prevention
Measures taken to identify patients at risk of over-medicalisation
Targets are patients with illness but no disease
Prevents harmful medical interventions
what are the disadvantages of classification systems
Classification systems are imperfect
Overlap between different types of prevention, and interventions may fall into more than one category
How can smoking cessation fall into primary, secondary and tertiary prevention?
Is all screening secondary prevention, or can some be classified as primary prevention?
what is screening
Screening is the presumptive identification of unrecognized disease or defect by the application of tests, examinations, or other procedures which can be applied rapidly.
what are the principles of screenings
- The condition should be an important health problem.
- There should be an accepted treatment for patients with recognized diseases.
- Facilities for diagnosis and treatment should be available.
- There should be a recognizable latent or early symptomatic phase.
- There should be a suitable test or examination.
- The test should be acceptable to the population.
- The natural history of the condition should be adequately understood.
- There should be an agreed policy on whom to treat as patients.
- The cost of case-finding should be economically balanced
- Case-finding should be a continuous process
what is the purpose of a screening test
detect potential disease indictators
what is the purpose of diagnostic tests
establish presence/absence of disease
what is the target population of screening tests
Large numbers of asymptomatic, but potentially at risk individuals
what is the target population of diagnostic test
Symptomatic individuals to establish diagnosis, or asymptomatic individuals with a positive screening test
what is the test method of screening tests
Simple, acceptable to patients and staff, should not be harmful
what is the test method of diagnostic test
maybe invasive, expensive but justifiable as necessary to establish diagnosis
what is the positive result threshold of a screening test
Generally chosen towards high sensitivity not to miss potential disease
what is the positive result threshold of a diagnostic test
Chosen towards high specificity (true negatives). More weight given to accuracy and precision than to patient acceptability
what is the postive result of a screening test
Essentially indicates suspicion of disease that warrants confirmation