Public Health Flashcards
(126 cards)
What is primary prevention?
Preventing a disease form occuring in the first place-eliminates RF contriburting?
List 3 examples of primary prevention?
Vaccines
change4life
5 a day
What is secondary prevention?
detecting a disease in its early or pre-clinical phase to alter its course
List 2 examples of secondary prevention?
all screening programmes (breast, Bowel, cervical cancer)
Heel prick
What is tertiary prevention?
attempting to slow down disease progression + prevent complications of a disease, helping people manage their illness effectively.
List an example of tertiary prevention?
diabetic foot care, attending rehab after a stroke to prevent immobility.
What is the purpose of screening?
identifies seemingly well individuals who may be at risk of a disease, in the hope of catching the disease at its early stage
what is sensitivity?
the proportion of people with the disease who are correctly identified by the screening test.
(True Positive) / (True Positive + False Negative)
What is specificity?
the proportion of people without the disease who are correctly excluded by the screening test.
(True Negative) / (True Negative+ False Positive)
What is PPV (Positive predictive value)?
the proportion with a positive test result
who actually have the disease. Dependent on underlying prevalence.
(True Positive) / (True Positive + False Positive)
What is NPV (Negative predictive value)?
the proportion with a negative test result
who do not have the disease. This is lower if the prevalence is higher.
(True Negative) / (True Negative+ False Negative)
List 2 disadvantages of screening?
Exposing well individuals to distressful or harmful diagnostic tests
Overtreatment of disease that may have never caused any problems
Preventative interventions may cause harm to the inividual or population
Reassurance to false negatives patients
What criteria is used fro screening?
Wilson and Junger
List 3 requirements for successful screening according to the wilson jungner criteria?
IATROGENIC
I- Important problem
A- Available diagnosis and treatment facility
T- Treatable
R- Recognisable latent stage
O- Obvious diagnostic test
G- General public accepted
E- Economically viable
N- Natural history understood
I- Issued agreed policy on who to treat
C- Continuously done
What is lead time bias?
Screening identifies diseases earlier and so gives the impression that survival is prolonged but in reality survival time is unchanged
What is length time bias?
Diseases with a longer period of presentation are more likely to be detected by screening than ones with a shorter time of presentation.
Describe the prevention paradox.
A preventative measure that brings much benefit to the population often offers little to each participating individual.
Give 4 different types of screening.
Population based.
Opportunistic.
Screening for communicable diseases.
Pre-employment and occupational.
What is the population approach to prevention? Give an example.
Preventative measures delivered on a population wide basis e.g. dietary salt reduction.
What is the high risk approach to prevention? Give an example.
Identifying individuals above a chosen cut-off and treating them. E.g. treating those with high cholesterol to avoid heart disease.
What is a RCT?
Where a population is randomised to either an interventional or a control group. Often these are blind or double-blind trials.
Which type of study follows a population over time to see if they’re exposed to the agent in question and if they develop the disease?
A cohort or incidence study. These are prospective.
Which type of study compares people with a disease to those without a disease for age, sex, habits, class etc?
A case-control study. These are retrospective.
Which type of study looks at the population at a point in time?
A cross-sectional or prevalence study.