Block 5 Flashcards
Major screening in the UK
Antenatal and newborn screening – Down’s Syndrome, Sickle Cell anaemia, hearing screen, physical examination etc.
Adults: AAA, breast cancer, cervical cancer, diabetic retinopathy, bowel cancer.
Define overdiagnosis
Correct diagnosis but not needed as never become symptomatic
Define overtreatment
Unnecessary treatment that doesn’t improve health
Outline Wilson-Junger criteria
PATHETIC Little Fuckers
Policy of who to treat, Acceptable test, Treatment exists, History of disease understood, Economically balanced, Test exists, Important health problem, Continuous, Latent period, Facilities available.
Define sensitivity
The likelihood that if you have a disease, the test will pick up that you have it and give you a positive result
Sensitivity equation
Sens = TP/(TP+FN)
Define specificity
The likelihood that if you do not have the disease, the test will identify you as free from disease
Specificity equation
Spec = TN/(TN+FP)
What is Positive Predictive Value (PPV)
The proportion of people tested as positive that are true positive.
Positive Predictive Value (PPV) equation
PPV = TP/(TP+FP)
Define Negative Predictive Value (NPV)
The proportion of people that have tested negative that are true negatives.
Negative predictive value (NPV) equation
NPV = TN/(TN+FN)
4 types of bias in screening
- Healthy Screenee - taking screening are more likely to be healthy
- Length time - more severe diseases versions are more likely to kill you before you are screened
- Lead time - Likely to pick up by screening before HCP would = just extends diagnosis time not prognosis improvement
- Overdiagnosis - diagnose healthy people and asymptomatic people
Newborn and pregnancy Screening in the UK
- Down’s Syndrome
- Fetal Anomaly Ultrasound Scan
- Infectious Diseases in Pregnancy
- Antenatal Sickle Cell and Thalassaemia
- Newborn and Infant Physical Examination
- Newborn Blood Spot
- Newborn Hearing Screening
