Screening Flashcards
What is mass screening?
Everyone is screened, regardless of risk factors
What is selective screening?
Screening is directed at selected populations that have a higher risk of a potential condition, e.g. abdominal aortic
aneurysm (risk factors - male, over 65y)
What is surveillance screening?
Monitoring of the long-term health of individuals, e.g. with BRCA2 mutations
What is opportunistic screening?
Screening performed in healthcare situations, e.g. HIV testing in A & E
What are the points of Wilson Jungner criteria?
1) Condition must be an important health problem
2) Accepted treatment for patients with organised disease
3) Facilities for diagnosis and treatment should be available
4) Recognisable latent or early symptomatic stage
5) Suitable test or examination
6) Acceptable to the population
7) Natural history should be understood
What is sensitivity?
Ability of the test to correctly identify those patients with the disease
What is specificity?
Specificity of a clinical test refers to the ability of the test to correctly identify those patients without the disease
What is positive predictive value (PPV)?
Probability following a positive test result, that individual will truly have that specific disease
What is negative predictive value (NPV)?
Probability that following a negative test result, that individual will truly not have that specific disease
How do you calculate sensitivity?
((True positive)/(True positive+False Negative ))×100
How do you calculate specificity?
(True negative / (True negative + False Positive))×100
How do you calculate PPV?
(TP / (TP + FP))×100
How do you calculate NPV?
(TN / (TN + FN))×100
What are the diseases tested in antennal screening?
Sickle cell disease / thalassaemia Foetal anomaly (Ultrasound scan at around 20 weeks, Trisomy 13, 18, 21) Infectious diseases (Hepatitis B, Syphillis, Rubella, HIV)
What are the diseases tested in newborn screening?
(3 diseases) Sickle cell disease (SCD) Congenital hypothyroidism (CHT) Cystic fibrosis (CF) (6 metabolic conditions) Phenylketonuria (PKU) Homocystinuria (HCY) Glutaric aciduria type 1 (GA1) Isovaleric aciduria (IVA) Medium chain acyl CoA Dehydrogenase Deficiency (MCADD) Maple syrup urine disease (MSUD)
