Session 8 Flashcards
What is the purpose of screening?
To identify people with a disease earlier than they would have if they were not screened.
To improve the health outcomes of a condition.
To reach everyone in the target population.
To reduce the chance of developing a serious condition or its complications.
What are the 3 types of screening programme?
Population.
Targeted.
Stratified.
What is the criteria for a screening programme?
Condition - the condition screened for must have a significant effect on someone and be relatively common.
Test - it must be a safe, simple, precise and validated test. It must be acceptable to the target population, and there must be something that can be done to confirm the diagnosis.
Intervention - there must be something that can be done to improve health outcomes after they have been confirmed to have the disease.
Screening programme - there must be a proven effectiveness in reducing morbidity/ mortality. There must be evidence that the programme is clinically, socially and ethically acceptable with the benefits outweighing the harms.
Implementation - it must be available to all that require it and be available continuously, with adequate staffing and facilities. There must be evidence-based information available to participants, allowing them to make the choice. Quality assurance and clinical outcomes should be optimised.
What are the advantages of screening?
It can help to diagnose a patient earlier.
It can help improve the outcomes of a patient.
It can decrease the cost required of treating the patient.
It can help to improve peoples health related behaviours.
What are the disadvantages of screening?
There may be false negatives or positives.
The condition may never have been clinically significant for the patient.
It can be stressful and be a cause of serious anxiety.
Overdiagnosis.
What are the barriers to screening?
Lack of time.
Lack of money to facilitate the transport there.
Uneducated on the importance of being screened.
Forgetting.
Poor access to screening facilities.
Mobility issues.
What is informed choice of a screening programme?
Where a patient has all of the information required around the benefits and drawbacks, the testing procedure, the condition being tested for and the outcomes of the screening programme, to be able to make their own decision on whether they wish to partake.
What is a diagnosis?
The definitive identification of a suspected disease or defect by application of tests, examinations or other procedures to label people as either having or not having a disease.
What are false positives and false negatives?
False positives = incorrectly diagnoses somebody as having a disease, when they do not.
False negatives = incorrectly diagnoses somebody as not having a disease, when they do.
What are the 4 features of test validity?
Sensitivity.
Specificity.
Positive predictive value.
Negative predictive value.
What is sensitivity?
The ability to detect a person who has a disease as having that disease. The proportion of people who have the disease that test positive.
How do you work out the sensitivity of a screening programme?
Divide the number of people that test positive for the disease by the number of people that are known to have the disease.
What is specificity?
The proportion of people without the disease who test negative.
How do you work out specificity?
Divide the number of people who tested negative by the number of people that do not have the disease.
What is the positive predictive value?
The probability that someone who tests positive actually has the disease.
